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DOE OSTI2020

Materials Data on Fe11Mo6C5 by Materials Project

Mo6Fe11C5 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Mo sites. In the first Mo site, Mo is bonded in a 2-coordinate geometry to one Fe and three C atoms. The Mo–Fe bond length is 2.71 Å. There are a spread of Mo–C bond distances ranging from 2.08–2.38 Å. In the second Mo site, Mo is bonded in a 2-coordinate geometry to one Fe and two equivalent C atoms. The Mo–Fe bond length is 2.78 Å. Both Mo–C bond lengths are 2.20 Å. There are five inequivalent Fe sites. In the first Fe site, Fe is bonded in a distorted water-like geometry to one Fe and two equivalent C atoms. The Fe–Fe bond length is 2.48 Å. There are one shorter (1.99 Å) and one longer (2.09 Å) Fe–C bond lengths. In the second Fe site, Fe is bonded in a distorted bent 150 degrees geometry to one Fe and two equivalent C atoms. The Fe–Fe bond length is 2.49 Å. Both Fe–C bond lengths are 1.94 Å. In the third Fe site, Fe is bonded in a single-bond geometry to one C atom. The Fe–C bond length is 1.93 Å. In the fourth Fe site, Fe is bonded in a bent 150 degrees geometry to two equivalent C atoms. Both Fe–C bond lengths are 1.98 Å. In the fifth Fe site, Fe is bonded to six Mo and six Fe atoms to form FeFe6Mo6 cuboctahedra that share edges with two equivalent CFe2Mo4 octahedra. There are two inequivalent C sites. In the first C site, C is bonded in a 7-coordinate geometry to three Mo and four Fe atoms. In the second C site, C is bonded to four equivalent Mo and two equivalent Fe atoms to form CFe2Mo4 octahedra that share edges with two equivalent FeFe6Mo6 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy2Fe17CN by Materials Project

Dy2Fe17CN crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Dy is bonded in a distorted bent 120 degrees geometry to nine Fe, one C, and one N atom. There are a spread of Dy–Fe bond distances ranging from 3.04–3.34 Å. The Dy–C bond length is 2.52 Å. The Dy–N bond length is 2.44 Å. There are ten inequivalent Fe sites. In the first Fe site, Fe is bonded in a 2-coordinate geometry to one Dy and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.39–2.77 Å. In the second Fe site, Fe is bonded in a single-bond geometry to five Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.47–2.59 Å. The Fe–C bond length is 1.91 Å. In the third Fe site, Fe is bonded in a single-bond geometry to five Fe and one N atom. There are a spread of Fe–Fe bond distances ranging from 2.47–2.56 Å. The Fe–N bond length is 1.92 Å. In the fourth Fe site, Fe is bonded to three equivalent Dy and nine Fe atoms to form FeDy3Fe9 cuboctahedra that share corners with eleven FeDy3Fe9 cuboctahedra, corners with two equivalent CDy2Fe4 octahedra, corners with two equivalent NDy2Fe4 octahedra, edges with four FeDy3Fe9 cuboctahedra, faces with eight FeDy3Fe9 cuboctahedra, a faceface with one CDy2Fe4 octahedra, and a faceface with one NDy2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 63–70°. There are a spread of Fe–Fe bond distances ranging from 2.45–2.60 Å. In the fifth Fe site, Fe is bonded to two equivalent Dy and ten Fe atoms to form FeDy2Fe10 cuboctahedra that share corners with eight FeDy3Fe9 cuboctahedra, corners with two equivalent CDy2Fe4 octahedra, edges with four FeDy3Fe9 cuboctahedra, faces with eight FeDy3Fe9 cuboctahedra, and faces with two equivalent NDy2Fe4 octahedra. The corner-sharing octahedral tilt angles are 44°. There are two shorter (2.43 Å) and two longer (2.45 Å) Fe–Fe bond lengths. In the sixth Fe site, Fe is bonded to two equivalent Dy and ten Fe atoms to form distorted FeDy2Fe10 cuboctahedra that share corners with eight FeDy3Fe9 cuboctahedra, corners with two equivalent NDy2Fe4 octahedra, edges with four FeDy2Fe10 cuboctahedra, faces with eight FeDy3Fe9 cuboctahedra, and faces with two equivalent CDy2Fe4 octahedra. The corner-sharing octahedral tilt angles are 44°. There are two shorter (2.43 Å) and two longer (2.44 Å) Fe–Fe bond lengths. In the seventh Fe site, Fe is bonded to two equivalent Dy and ten Fe atoms to form distorted FeDy2Fe10 cuboctahedra that share corners with fourteen FeDy3Fe9 cuboctahedra, edges with two equivalent FeDy3Fe9 cuboctahedra, faces with ten FeDy3Fe9 cuboctahedra, faces with two equivalent CDy2Fe4 octahedra, and faces with two equivalent NDy2Fe4 octahedra. There are two shorter (2.43 Å) and two longer (2.44 Å) Fe–Fe bond lengths. In the eighth Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. The Fe–Fe bond length is 2.47 Å. The Fe–C bond length is 1.85 Å. In the ninth Fe site, Fe is bonded in a single-bond geometry to six Fe and one N atom. The Fe–Fe bond length is 2.49 Å. The Fe–N bond length is 1.89 Å. In the tenth Fe site, Fe is bonded to two equivalent Dy and ten Fe atoms to form distorted FeDy2Fe10 cuboctahedra that share corners with eight FeDy3Fe9 cuboctahedra, corners with two equivalent CDy2Fe4 octahedra, corners with two equivalent NDy2Fe4 octahedra, edges with three FeDy2Fe10 cuboctahedra, an edgeedge with one CDy2Fe4 octahedra, an edgeedge with one NDy2Fe4 octahedra, and faces with nine FeDy3Fe9 cuboctahedra. The corner-sharing octahedra tilt angles range from 23–29°. C is bonded to two equivalent Dy and four Fe atoms to form CDy2Fe4 octahedra that share corners with ten FeDy3Fe9 cuboctahedra, corners with two equivalent NDy2Fe4 octahedra, edges with two equivalent FeDy2Fe10 cuboctahedra, and faces with six FeDy2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 62°. N is bonded to two equivalent Dy and four Fe atoms to form NDy2Fe4 octahedra that share corners with ten FeDy3Fe9 cuboctahedra, corners with two equivalent CDy2Fe4 octahedra, edges with two equivalent FeDy2Fe10 cuboctahedra, and faces with six FeDy2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 62°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeO2 by Materials Project

FeO2 is Cyanogen Chloride-derived structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is zero-dimensional and consists of two iron dihydroxide molecules. Fe is bonded in a linear geometry to two equivalent O atoms. Both Fe–O bond lengths are 1.59 Å. O is bonded in a single-bond geometry to one Fe atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeO2 by Materials Project

FeO2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four iron dihydroxide molecules. Fe is bonded in a distorted linear geometry to two equivalent O atoms. Both Fe–O bond lengths are 1.32 Å. O is bonded in a single-bond geometry to one Fe atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SmErFe17C2 by Materials Project

ErSmFe17C2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Er is bonded in a distorted bent 120 degrees geometry to nine Fe and two equivalent C atoms. There are a spread of Er–Fe bond distances ranging from 3.02–3.39 Å. Both Er–C bond lengths are 2.48 Å. Sm is bonded in a distorted bent 120 degrees geometry to nine Fe and two equivalent C atoms. There are a spread of Sm–Fe bond distances ranging from 3.04–3.36 Å. Both Sm–C bond lengths are 2.56 Å. There are eleven inequivalent Fe sites. In the first Fe site, Fe is bonded in a 2-coordinate geometry to one Er and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.38–2.77 Å. In the second Fe site, Fe is bonded in a 2-coordinate geometry to one Sm and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.65–2.77 Å. In the third Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.44–2.56 Å. The Fe–C bond length is 1.86 Å. In the fourth Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.43–2.57 Å. The Fe–C bond length is 1.86 Å. In the fifth Fe site, Fe is bonded in a 12-coordinate geometry to one Er, one Sm, and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.45–2.63 Å. In the sixth Fe site, Fe is bonded in a single-bond geometry to five Fe and one C atom. There are two shorter (2.48 Å) and one longer (2.53 Å) Fe–Fe bond lengths. The Fe–C bond length is 1.91 Å. In the seventh Fe site, Fe is bonded to one Er, two equivalent Sm, and nine Fe atoms to form FeSm2ErFe9 cuboctahedra that share corners with nine FeSm2ErFe9 cuboctahedra, corners with four equivalent CSmErFe4 octahedra, edges with four FeSmEr2Fe9 cuboctahedra, faces with four FeSmEr2Fe9 cuboctahedra, and faces with two equivalent CSmErFe4 octahedra. The corner-sharing octahedra tilt angles range from 64–68°. There are two shorter (2.48 Å) and two longer (2.53 Å) Fe–Fe bond lengths. In the eighth Fe site, Fe is bonded in a single-bond geometry to five Fe and one C atom. Both Fe–Fe bond lengths are 2.47 Å. The Fe–C bond length is 1.92 Å. In the ninth Fe site, Fe is bonded to two equivalent Er, one Sm, and nine Fe atoms to form distorted FeSmEr2Fe9 cuboctahedra that share corners with nine FeSm2ErFe9 cuboctahedra, corners with four equivalent CSmErFe4 octahedra, edges with four FeSm2ErFe9 cuboctahedra, faces with four FeSm2ErFe9 cuboctahedra, and faces with two equivalent CSmErFe4 octahedra. The corner-sharing octahedra tilt angles range from 64–68°. Both Fe–Fe bond lengths are 2.46 Å. In the tenth Fe site, Fe is bonded to one Er, one Sm, and ten Fe atoms to form FeSmErFe10 cuboctahedra that share corners with six FeSm2ErFe9 cuboctahedra, corners with two equivalent CSmErFe4 octahedra, edges with two FeSm2ErFe9 cuboctahedra, faces with six FeSm2ErFe9 cuboctahedra, and faces with two equivalent CSmErFe4 octahedra. The corner-sharing octahedra tilt angles range from 43–44°. In the eleventh Fe site, Fe is bonded to one Er, one Sm, and ten Fe atoms to form distorted FeSmErFe10 cuboctahedra that share corners with ten FeSm2ErFe9 cuboctahedra, edges with two FeSmEr2Fe9 cuboctahedra, faces with six FeSm2ErFe9 cuboctahedra, and faces with four equivalent CSmErFe4 octahedra. C is bonded to one Er, one Sm, and four Fe atoms to form CSmErFe4 octahedra that share corners with six FeSm2ErFe9 cuboctahedra, corners with two equivalent CSmErFe4 octahedra, and faces with six FeSmEr2Fe9 cuboctahedra. The corner-sharing octahedral tilt angles are 63°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg14FeCo by Materials Project

Mg14FeCo crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are seven inequivalent Mg sites. In the first Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent CoMg10Fe2 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with six MgMg12 cuboctahedra, faces with two equivalent FeMg10Co2 cuboctahedra, and faces with six MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.07–3.22 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent FeMg10Co2 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with six MgMg12 cuboctahedra, faces with two equivalent CoMg10Fe2 cuboctahedra, and faces with six MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.07–3.22 Å. In the third Mg site, Mg is bonded to eight Mg, two equivalent Fe, and two equivalent Co atoms to form distorted MgMg8Fe2Co2 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent MgMg8Fe2Co2 cuboctahedra, edges with two equivalent FeMg10Co2 cuboctahedra, edges with two equivalent CoMg10Fe2 cuboctahedra, faces with two equivalent FeMg10Co2 cuboctahedra, faces with two equivalent CoMg10Fe2 cuboctahedra, and faces with four MgMg8Fe2Co2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.89–3.14 Å. There are one shorter (3.01 Å) and one longer (3.22 Å) Mg–Fe bond lengths. There are one shorter (3.02 Å) and one longer (3.22 Å) Mg–Co bond lengths. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent FeMg10Co2 cuboctahedra, corners with four equivalent CoMg10Fe2 cuboctahedra, corners with ten MgMg8Fe2Co2 cuboctahedra, edges with six MgMg12 cuboctahedra, and faces with eight MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.12–3.29 Å. In the fifth Mg site, Mg is bonded in a 12-coordinate geometry to four Mg, one Fe, and one Co atom. The Mg–Fe bond length is 2.78 Å. The Mg–Co bond length is 2.79 Å. In the sixth Mg site, Mg is bonded in a distorted single-bond geometry to five Mg and one Fe atom. The Mg–Fe bond length is 2.85 Å. In the seventh Mg site, Mg is bonded in a distorted single-bond geometry to five Mg and one Co atom. The Mg–Co bond length is 2.86 Å. Fe is bonded to ten Mg and two equivalent Co atoms to form distorted FeMg10Co2 cuboctahedra that share corners with six equivalent FeMg10Co2 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent CoMg10Fe2 cuboctahedra, edges with four equivalent MgMg8Fe2Co2 cuboctahedra, faces with two equivalent CoMg10Fe2 cuboctahedra, and faces with six MgMg12 cuboctahedra. Both Fe–Co bond lengths are 3.12 Å. Co is bonded to ten Mg and two equivalent Fe atoms to form distorted CoMg10Fe2 cuboctahedra that share corners with six equivalent CoMg10Fe2 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent FeMg10Co2 cuboctahedra, edges with four equivalent MgMg8Fe2Co2 cuboctahedra, faces with two equivalent FeMg10Co2 cuboctahedra, and faces with six MgMg12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeBP2O11 by Materials Project

(FeB(PO5)2)2O2 crystallizes in the hexagonal P6_122 space group. The structure is three-dimensional and consists of six water molecules and one FeB(PO5)2 framework. In the FeB(PO5)2 framework, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four equivalent PO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.72–1.99 Å. B is bonded to four O atoms to form BO4 tetrahedra that share corners with four equivalent PO4 tetrahedra. There is two shorter (1.47 Å) and two longer (1.48 Å) B–O bond length. P is bonded to four O atoms to form PO4 tetrahedra that share corners with two equivalent FeO6 octahedra and corners with two equivalent BO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–50°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. There are five inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to one B and one P atom. In the second O site, O is bonded in a single-bond geometry to one Fe atom. In the third O site, O is bonded in a bent 120 degrees geometry to one B and one P atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to one Fe and one P atom. In the fifth O site, O is bonded in a bent 120 degrees geometry to one Fe and one P atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm2Fe17CN by Materials Project

Sm2Fe17CN crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Sm is bonded in a distorted bent 120 degrees geometry to nine Fe, one C, and one N atom. There are a spread of Sm–Fe bond distances ranging from 3.08–3.36 Å. The Sm–C bond length is 2.56 Å. The Sm–N bond length is 2.48 Å. There are ten inequivalent Fe sites. In the first Fe site, Fe is bonded in a 2-coordinate geometry to one Sm and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.37–2.75 Å. In the second Fe site, Fe is bonded in a single-bond geometry to five Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.47–2.57 Å. The Fe–C bond length is 1.91 Å. In the third Fe site, Fe is bonded in a single-bond geometry to five Fe and one N atom. There are a spread of Fe–Fe bond distances ranging from 2.48–2.57 Å. The Fe–N bond length is 1.93 Å. In the fourth Fe site, Fe is bonded to three equivalent Sm and nine Fe atoms to form FeSm3Fe9 cuboctahedra that share corners with eleven FeSm3Fe9 cuboctahedra, corners with two equivalent CSm2Fe4 octahedra, corners with two equivalent NSm2Fe4 octahedra, edges with four FeSm3Fe9 cuboctahedra, faces with eight FeSm3Fe9 cuboctahedra, a faceface with one CSm2Fe4 octahedra, and a faceface with one NSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 63–70°. There are a spread of Fe–Fe bond distances ranging from 2.48–2.66 Å. In the fifth Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. There are two shorter (2.44 Å) and one longer (2.47 Å) Fe–Fe bond lengths. The Fe–C bond length is 1.86 Å. In the sixth Fe site, Fe is bonded in a single-bond geometry to six Fe and one N atom. There are two shorter (2.44 Å) and one longer (2.48 Å) Fe–Fe bond lengths. The Fe–N bond length is 1.89 Å. In the seventh Fe site, Fe is bonded to two equivalent Sm and ten Fe atoms to form distorted FeSm2Fe10 cuboctahedra that share corners with eight FeSm3Fe9 cuboctahedra, corners with two equivalent CSm2Fe4 octahedra, corners with two equivalent NSm2Fe4 octahedra, edges with three FeSm2Fe10 cuboctahedra, an edgeedge with one CSm2Fe4 octahedra, an edgeedge with one NSm2Fe4 octahedra, and faces with nine FeSm3Fe9 cuboctahedra. The corner-sharing octahedra tilt angles range from 22–29°. There are one shorter (2.44 Å) and one longer (2.45 Å) Fe–Fe bond lengths. In the eighth Fe site, Fe is bonded to two equivalent Sm and ten Fe atoms to form FeSm2Fe10 cuboctahedra that share corners with eight FeSm3Fe9 cuboctahedra, corners with two equivalent CSm2Fe4 octahedra, edges with four FeSm2Fe10 cuboctahedra, faces with eight FeSm3Fe9 cuboctahedra, and faces with two equivalent NSm2Fe4 octahedra. The corner-sharing octahedral tilt angles are 44°. In the ninth Fe site, Fe is bonded to two equivalent Sm and ten Fe atoms to form distorted FeSm2Fe10 cuboctahedra that share corners with eight FeSm3Fe9 cuboctahedra, corners with two equivalent NSm2Fe4 octahedra, edges with four FeSm2Fe10 cuboctahedra, faces with eight FeSm3Fe9 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The corner-sharing octahedral tilt angles are 44°. In the tenth Fe site, Fe is bonded to two equivalent Sm and ten Fe atoms to form distorted FeSm2Fe10 cuboctahedra that share corners with fourteen FeSm3Fe9 cuboctahedra, edges with two equivalent FeSm3Fe9 cuboctahedra, faces with ten FeSm3Fe9 cuboctahedra, faces with two equivalent CSm2Fe4 octahedra, and faces with two equivalent NSm2Fe4 octahedra. C is bonded to two equivalent Sm and four Fe atoms to form CSm2Fe4 octahedra that share corners with ten FeSm3Fe9 cuboctahedra, corners with two equivalent NSm2Fe4 octahedra, edges with two equivalent FeSm2Fe10 cuboctahedra, and faces with six FeSm2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 62°. N is bonded to two equivalent Sm and four Fe atoms to form NSm2Fe4 octahedra that share corners with ten FeSm3Fe9 cuboctahedra, corners with two equivalent CSm2Fe4 octahedra, edges with two equivalent FeSm2Fe10 cuboctahedra, and faces with six FeSm2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 62°.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Single-Atomic Site Catalyst Enhanced Lateral Flow Immunoassay for Point-of-Care Detection of Herbicide

Point-of-care (POC) detection of herbicides is of great importance due to their impact on the environment and potential risks to human health. Here, we design a single-atomic site catalyst (SASC) with excellent peroxidase-like (POD-like) catalytic activity, which enhances the detection performance of corresponding lateral flow immunoassay (LFIA). The iron single-atomic site catalyst (Fe-SASC) is synthesized from hemin-doped ZIF-8, creating active sites that mimic the Fe active center coordination environment of natural enzyme and their functions. Due to its atomically dispersed iron active sites that result in maximum utilization of active metal atoms, the Fe-SASC exhibits superior POD-like activity, which has great potential to replace its natural counterparts. Also, the catalytic mechanism of Fe-SASC is systematically investigated. Utilizing its outstanding catalytic activity, the Fe-SASC is used as label to construct LFIA (Fe-SASC-LFIA) for herbicide detection. The 2,4-dichlorophenoxyacetic acid (2,4-D) is selected as a target here, since it is a commonly used herbicide as well as a biomarker for herbicide exposure evaluation. A linear detection range of 1-250 ng/mL with a low limit of detection (LOD) of 0.82 ng/mL has been achieved. Meanwhile, excellent specificity and selectivity towards 2,4-D have been obtained. The outstanding detection performance of the Fe-SASC-LFIA has also been demonstrated in the detection of human urine samples, indicating the practicability of this POC detection platform for analyzing the 2,4-D exposure level of a person. We believe this proposed Fe-SASC-LFIA has potential as a portable, rapid, and high-sensitive POC detection strategy for pesticide exposure evaluation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on Tb2Fe17CN by Materials Project

Tb2Fe17CN crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Tb is bonded in a distorted bent 120 degrees geometry to nine Fe, one C, and one N atom. There are a spread of Tb–Fe bond distances ranging from 3.06–3.34 Å. The Tb–C bond length is 2.53 Å. The Tb–N bond length is 2.45 Å. There are ten inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.43–2.74 Å. The Fe–C bond length is 1.85 Å. In the second Fe site, Fe is bonded in a single-bond geometry to six Fe and one N atom. There are a spread of Fe–Fe bond distances ranging from 2.43–2.72 Å. The Fe–N bond length is 1.88 Å. In the third Fe site, Fe is bonded to two equivalent Tb and ten Fe atoms to form distorted FeTb2Fe10 cuboctahedra that share corners with eight FeTb2Fe10 cuboctahedra, corners with two equivalent CTb2Fe4 octahedra, corners with two equivalent NTb2Fe4 octahedra, edges with three FeTb2Fe10 cuboctahedra, an edgeedge with one CTb2Fe4 octahedra, an edgeedge with one NTb2Fe4 octahedra, and faces with nine FeTb2Fe10 cuboctahedra. The corner-sharing octahedra tilt angles range from 23–29°. There are a spread of Fe–Fe bond distances ranging from 2.44–2.76 Å. In the fourth Fe site, Fe is bonded in a 2-coordinate geometry to one Tb and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.38–2.67 Å. In the fifth Fe site, Fe is bonded in a single-bond geometry to five Fe and one C atom. There are two shorter (2.47 Å) and one longer (2.52 Å) Fe–Fe bond lengths. The Fe–C bond length is 1.92 Å. In the sixth Fe site, Fe is bonded in a single-bond geometry to five Fe and one N atom. There are two shorter (2.48 Å) and one longer (2.54 Å) Fe–Fe bond lengths. The Fe–N bond length is 1.93 Å. In the seventh Fe site, Fe is bonded to three equivalent Tb and nine Fe atoms to form FeTb3Fe9 cuboctahedra that share corners with eleven FeTb2Fe10 cuboctahedra, corners with two equivalent CTb2Fe4 octahedra, corners with two equivalent NTb2Fe4 octahedra, edges with four FeTb3Fe9 cuboctahedra, faces with eight FeTb2Fe10 cuboctahedra, a faceface with one CTb2Fe4 octahedra, and a faceface with one NTb2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 63–69°. Both Fe–Fe bond lengths are 2.46 Å. In the eighth Fe site, Fe is bonded to two equivalent Tb and ten Fe atoms to form FeTb2Fe10 cuboctahedra that share corners with eight FeTb2Fe10 cuboctahedra, corners with two equivalent CTb2Fe4 octahedra, edges with four FeTb3Fe9 cuboctahedra, faces with eight FeTb2Fe10 cuboctahedra, and faces with two equivalent NTb2Fe4 octahedra. The corner-sharing octahedral tilt angles are 44°. In the ninth Fe site, Fe is bonded to two equivalent Tb and ten Fe atoms to form FeTb2Fe10 cuboctahedra that share corners with eight FeTb2Fe10 cuboctahedra, corners with two equivalent NTb2Fe4 octahedra, edges with four FeTb3Fe9 cuboctahedra, faces with eight FeTb2Fe10 cuboctahedra, and faces with two equivalent CTb2Fe4 octahedra. The corner-sharing octahedral tilt angles are 44°. In the tenth Fe site, Fe is bonded to two equivalent Tb and ten Fe atoms to form FeTb2Fe10 cuboctahedra that share corners with fourteen FeTb2Fe10 cuboctahedra, edges with two equivalent FeTb3Fe9 cuboctahedra, faces with ten FeTb2Fe10 cuboctahedra, faces with two equivalent CTb2Fe4 octahedra, and faces with two equivalent NTb2Fe4 octahedra. C is bonded to two equivalent Tb and four Fe atoms to form CTb2Fe4 octahedra that share corners with ten FeTb2Fe10 cuboctahedra, corners with two equivalent NTb2Fe4 octahedra, edges with two equivalent FeTb2Fe10 cuboctahedra, and faces with six FeTb2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 61°. N is bonded to two equivalent Tb and four Fe atoms to form NTb2Fe4 octahedra that share corners with ten FeTb2Fe10 cuboctahedra, corners with two equivalent CTb2Fe4 octahedra, edges with two equivalent FeTb2Fe10 cuboctahedra, and faces with six FeTb2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 61°.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Metal–Metal Oxide Catalytic Interface Formation and Structural Evolution: A Discovery of Strong Metal–Support Bonding, Ordered Intermetallics, and Single Atoms

In-depth investigation of metal–metal oxide interactions and their corresponding evolution is of paramount importance to heterogeneous catalysis as it allows the understanding and maneuvering of the structure of catalytic motifs. Herein, using a series of core/shell metal/iron oxide (M/FeO x , M = Pd, Pt, Au) nanoparticles and through a combination of in situ and ex situ electron and X-ray investigations, we revealed anomalous and dissimilar M–FeO x interactions among different systems under reducing conditions. Further, Pd interacts strongly with FeO x after high-temperature reductive treatment, featured by the formation of Pd single atoms in the FeO x matrix and increased Pd–Fe bonding, while Pt transforms into ordered PtFe intermetallics and Pt single atoms immediately upon the coating of FeO x . In contrast, Au does not manifest strong bonding with FeO x . As a proof of concept of tailoring metal–metal oxide interactions for catalysis, optimized Pd/FeO x demonstrates 100% conversion and 86.5% selectivity at 60 °C for acetylene semihydrogenation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Understanding the Active Site Structures and Achieving Catalytic Activity Tuning of Atomically Dispersed FeN 4 Sites for Oxygen Reduction Reaction

Atomically dispersed Fe–—N—C catalysts with high oxygen reduction reaction (ORR) activity have attracted great attention since the last decade. Due to comparable ORR activity and low material cost, they are promising platinum group metal (PGM)-free catalysts that can replace the commercialized Pt/C materials; furthermore, it can facilitate the efficiency of the fuel cell technologies and mitigate dependence on fossil fuels. Great advancements have been made to experimentally optimize the synthesis approach of the Fe–—N—C catalysts, enhance the ORR activity, and improve the catalyst stability. Similarly, recent theoretical studies also provide enriched understanding of the active site structures, properties, and reaction mechanisms. In this review, discussions are made upon utilizing combined experimental and computational spectroscopy to reveal the active site structures, employing mechanistic studies to investigate reaction thermodynamics and kinetics, as well as developing scaling relationships to assist the design and development of future PGM-free catalyst materials. Furthermore, recent advances in studying Fe–—N—C catalysts utilizing electrified surface models and explicit solvation models are also discussed. Not only can these aspects improve the accuracy of theoretical simulation and predictions but also deepen the understanding of the catalyst properties and reaction mechanisms under the effect of surface charges and solvent molecules.

Fe single-atom catalysts↗
DOE OSTI2020

Materials Data on Sm4Fe27Co7C2 by Materials Project

Sm4Fe27Co7C2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Sm sites. In the first Sm site, Sm is bonded in a distorted single-bond geometry to ten Fe, four Co, and one C atom. There are a spread of Sm–Fe bond distances ranging from 3.03–3.32 Å. There are a spread of Sm–Co bond distances ranging from 3.07–3.34 Å. The Sm–C bond length is 2.55 Å. In the second Sm site, Sm is bonded in a distorted single-bond geometry to eleven Fe, three Co, and one C atom. There are a spread of Sm–Fe bond distances ranging from 3.04–3.31 Å. There are one shorter (3.27 Å) and two longer (3.34 Å) Sm–Co bond lengths. The Sm–C bond length is 2.56 Å. In the third Sm site, Sm is bonded in a distorted single-bond geometry to eleven Fe, three Co, and one C atom. There are a spread of Sm–Fe bond distances ranging from 3.04–3.30 Å. There are one shorter (3.27 Å) and two longer (3.34 Å) Sm–Co bond lengths. The Sm–C bond length is 2.56 Å. In the fourth Sm site, Sm is bonded in a distorted single-bond geometry to eleven Fe, three Co, and one C atom. There are a spread of Sm–Fe bond distances ranging from 3.03–3.30 Å. There are one shorter (3.27 Å) and two longer (3.34 Å) Sm–Co bond lengths. The Sm–C bond length is 2.55 Å. There are seventeen inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to five Fe, two equivalent Co, and one C atom. There are four shorter (2.55 Å) and one longer (2.67 Å) Fe–Fe bond lengths. Both Fe–Co bond lengths are 2.48 Å. The Fe–C bond length is 1.93 Å. In the second Fe site, Fe is bonded in a single-bond geometry to five Fe, two equivalent Co, and one C atom. There are four shorter (2.56 Å) and one longer (2.66 Å) Fe–Fe bond lengths. Both Fe–Co bond lengths are 2.47 Å. The Fe–C bond length is 1.92 Å. In the third Fe site, Fe is bonded to three Sm, seven Fe, and two Co atoms to form distorted FeSm3Fe7Co2 cuboctahedra that share corners with five CoSm2Fe10 cuboctahedra, corners with seven FeSm3Fe7Co2 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with three FeSm3Fe7Co2 cuboctahedra, edges with three CoSm2Fe10 cuboctahedra, faces with three CoSm2Fe10 cuboctahedra, faces with four FeSm3Fe7Co2 cuboctahedra, and a faceface with one CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 66–70°. There are a spread of Fe–Fe bond distances ranging from 2.54–2.67 Å. There are one shorter (2.47 Å) and one longer (2.48 Å) Fe–Co bond lengths. In the fourth Fe site, Fe is bonded to three Sm, seven Fe, and two Co atoms to form distorted FeSm3Fe7Co2 cuboctahedra that share corners with five CoSm2Fe10 cuboctahedra, corners with seven FeSm3Fe7Co2 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with three FeSm3Fe7Co2 cuboctahedra, edges with three CoSm2Fe10 cuboctahedra, faces with three CoSm2Fe9Co cuboctahedra, faces with four FeSm3Fe7Co2 cuboctahedra, and a faceface with one CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 66–70°. There are a spread of Fe–Fe bond distances ranging from 2.54–2.67 Å. Both Fe–Co bond lengths are 2.47 Å. In the fifth Fe site, Fe is bonded in a single-bond geometry to five Fe, two equivalent Co, and one C atom. There are two shorter (2.56 Å) and one longer (2.66 Å) Fe–Fe bond lengths. Both Fe–Co bond lengths are 2.48 Å. The Fe–C bond length is 1.92 Å. In the sixth Fe site, Fe is bonded in a single-bond geometry to four Fe, three Co, and one C atom. Both Fe–Fe bond lengths are 2.55 Å. There are two shorter (2.47 Å) and one longer (2.64 Å) Fe–Co bond lengths. The Fe–C bond length is 1.92 Å. In the seventh Fe site, Fe is bonded to three Sm, six Fe, and three Co atoms to form distorted FeSm3Fe6Co3 cuboctahedra that share corners with five CoSm2Fe10 cuboctahedra, corners with seven FeSm3Fe7Co2 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with three FeSm3Fe7Co2 cuboctahedra, edges with three CoSm2Fe9Co cuboctahedra, faces with three CoSm2Fe9Co cuboctahedra, faces with four FeSm3Fe7Co2 cuboctahedra, and a faceface with one CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 66–70°. There are a spread of Fe–Fe bond distances ranging from 2.53–2.67 Å. There are a spread of Fe–Co bond distances ranging from 2.46–2.63 Å. In the eighth Fe site, Fe is bonded to three Sm, seven Fe, and two Co atoms to form distorted FeSm3Fe7Co2 cuboctahedra that share corners with five CoSm2Fe10 cuboctahedra, corners with seven FeSm3Fe7Co2 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with three FeSm3Fe7Co2 cuboctahedra, edges with three CoSm2Fe10 cuboctahedra, faces with three CoSm2Fe10 cuboctahedra, faces with four FeSm3Fe7Co2 cuboctahedra, and a faceface with one CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 66–70°. There are a spread of Fe–Fe bond distances ranging from 2.54–2.67 Å. Both Fe–Co bond lengths are 2.47 Å. In the ninth Fe site, Fe is bonded in a single-bond geometry to six Fe, two equivalent Co, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.47–2.74 Å. Both Fe–Co bond lengths are 2.44 Å. The Fe–C bond length is 1.85 Å. In the tenth Fe site, Fe is bonded in a single-bond geometry to five Fe, three Co, and one C atom. There are two shorter (2.47 Å) and one longer (2.73 Å) Fe–Fe bond lengths. There are two shorter (2.44 Å) and one longer (2.74 Å) Fe–Co bond lengths. The Fe–C bond length is 1.84 Å. In the eleventh Fe site, Fe is bonded in a 12-coordinate geometry to two Sm, eight Fe, and two Co atoms. There are a spread of Fe–Fe bond distances ranging from 2.48–2.75 Å. There are one shorter (2.43 Å) and one longer (2.44 Å) Fe–Co bond lengths. In the twelfth Fe site, Fe is bonded in a 12-coordinate geometry to two Sm, seven Fe, and three Co atoms. There are one shorter (2.49 Å) and one longer (2.73 Å) Fe–Fe bond lengths. There are a spread of Fe–Co bond distances ranging from 2.42–2.73 Å. In the thirteenth Fe site, Fe is bonded in a 12-coordinate geometry to two Sm, seven Fe, and three Co atoms. There are one shorter (2.50 Å) and one longer (2.73 Å) Fe–Fe bond lengths. There are a spread of Fe–Co bond distances ranging from 2.42–2.75 Å. In the fourteenth Fe site, Fe is bonded in a 12-coordinate geometry to two Sm, eight Fe, and two Co atoms. There are a spread of Fe–Fe bond distances ranging from 2.49–2.75 Å. There are one shorter (2.43 Å) and one longer (2.44 Å) Fe–Co bond lengths. In the fifteenth Fe site, Fe is bonded in a 5-coordinate geometry to one Sm, ten Fe, and three Co atoms. The Fe–Fe bond length is 2.36 Å. All Fe–Co bond lengths are 2.64 Å. In the sixteenth Fe site, Fe is bonded in a 5-coordinate geometry to one Sm, ten Fe, and three Co atoms. There are one shorter (2.64 Å) and two longer (2.65 Å) Fe–Co bond lengths. In the seventeenth Fe site, Fe is bonded in a 1-coordinate geometry to one Sm, nine Fe, and four Co atoms. There are a spread of Fe–Co bond distances ranging from 2.33–2.66 Å. There are five inequivalent Co sites. In the first Co site, Co is bonded to two Sm, nine Fe, and one Co atom to form distorted CoSm2Fe9Co cuboctahedra that share corners with four FeSm3Fe7Co2 cuboctahedra, corners with four CoSm2Fe10 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with four FeSm3Fe7Co2 cuboctahedra, faces with four FeSm3Fe7Co2 cuboctahedra, and faces with four CoSm2Fe9Co cuboctahedra. The corner-sharing octahedral tilt angles are 45°. The Co–Co bond length is 2.63 Å. In the second Co site, Co is bonded to two Sm and ten Fe atoms to form distorted CoSm2Fe10 cuboctahedra that share corners with four FeSm3Fe7Co2 cuboctahedra, corners with four CoSm2Fe10 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with four FeSm3Fe7Co2 cuboctahedra, faces with four FeSm3Fe7Co2 cuboctahedra, and faces with four CoSm2Fe9Co cuboctahedra. The corner-sharing octahedral tilt angles are 45°. In the third Co site, Co is bonded to two Sm and ten Fe atoms to form distorted CoSm2Fe10 cuboctahedra that share corners with four CoSm2Fe10 cuboctahedra, corners with eight FeSm3Fe7Co2 cuboctahedra, edges with four FeSm3Fe7Co2 cuboctahedra, faces with four FeSm3Fe7Co2 cuboctahedra, faces with four CoSm2Fe10 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. In the fourth Co site, Co is bonded to two Sm, nine Fe, and one Co atom to form distorted CoSm2Fe9Co cuboctahedra that share corners with four CoSm2Fe9Co cuboctahedra, corners with eight FeSm3Fe7Co2 cuboctahedra, edges with four FeSm3Fe7Co2 cuboctahedra, faces with four FeSm3Fe7Co2 cuboctahedra, faces with four CoSm2Fe9Co cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The Co–Co bond length is 2.65 Å. In the fifth Co site, Co is bonded in a 1-coordinate geometry to one Sm, ten Fe, and three Co atoms. There are two inequivalent C sites. In the first C site, C is bonded to two Sm and four Fe atoms to form CSm2Fe4 octahedra that share corners with two CoSm2Fe9Co cuboctahedra, corners with eight FeSm3Fe7Co2 cuboctahedra, faces with four FeSm3Fe7Co2 cuboctahedra, and faces with four equivalent CoSm2Fe10 cuboctahedra. In the second C site, C is bonded to two Sm and four Fe atoms to form CSm2Fe4 octahedra that share corners with two CoSm2Fe9Co cuboctahedra, corners with eight FeSm3Fe7Co2 cuboctahedra, faces with four FeSm3Fe6Co3 cuboctahedra, and faces with four equivalent CoSm2Fe9Co cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y2Fe17CN by Materials Project

Y2Fe17CN crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Y is bonded in a distorted bent 120 degrees geometry to nine Fe, one C, and one N atom. There are a spread of Y–Fe bond distances ranging from 3.06–3.34 Å. The Y–C bond length is 2.52 Å. The Y–N bond length is 2.45 Å. There are ten inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to five Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.46–2.64 Å. The Fe–C bond length is 1.91 Å. In the second Fe site, Fe is bonded in a single-bond geometry to five Fe and one N atom. There are a spread of Fe–Fe bond distances ranging from 2.47–2.65 Å. The Fe–N bond length is 1.92 Å. In the third Fe site, Fe is bonded to three equivalent Y and nine Fe atoms to form FeY3Fe9 cuboctahedra that share corners with eleven FeY3Fe9 cuboctahedra, corners with two equivalent CY2Fe4 octahedra, corners with two equivalent NY2Fe4 octahedra, edges with four FeY3Fe9 cuboctahedra, faces with eight FeY3Fe9 cuboctahedra, a faceface with one CY2Fe4 octahedra, and a faceface with one NY2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 63–70°. There are a spread of Fe–Fe bond distances ranging from 2.45–2.67 Å. In the fourth Fe site, Fe is bonded in a 2-coordinate geometry to one Y and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.38–2.75 Å. In the fifth Fe site, Fe is bonded to two equivalent Y and ten Fe atoms to form FeY2Fe10 cuboctahedra that share corners with eight FeY3Fe9 cuboctahedra, corners with two equivalent CY2Fe4 octahedra, edges with four FeY3Fe9 cuboctahedra, faces with eight FeY3Fe9 cuboctahedra, and faces with two equivalent NY2Fe4 octahedra. The corner-sharing octahedral tilt angles are 44°. There are two shorter (2.44 Å) and two longer (2.45 Å) Fe–Fe bond lengths. In the sixth Fe site, Fe is bonded to two equivalent Y and ten Fe atoms to form distorted FeY2Fe10 cuboctahedra that share corners with eight FeY3Fe9 cuboctahedra, corners with two equivalent NY2Fe4 octahedra, edges with four FeY3Fe9 cuboctahedra, faces with eight FeY3Fe9 cuboctahedra, and faces with two equivalent CY2Fe4 octahedra. The corner-sharing octahedral tilt angles are 44°. There are two shorter (2.43 Å) and two longer (2.44 Å) Fe–Fe bond lengths. In the seventh Fe site, Fe is bonded to two equivalent Y and ten Fe atoms to form distorted FeY2Fe10 cuboctahedra that share corners with fourteen FeY3Fe9 cuboctahedra, edges with two equivalent FeY3Fe9 cuboctahedra, faces with ten FeY3Fe9 cuboctahedra, faces with two equivalent CY2Fe4 octahedra, and faces with two equivalent NY2Fe4 octahedra. There are two shorter (2.43 Å) and two longer (2.44 Å) Fe–Fe bond lengths. In the eighth Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. The Fe–Fe bond length is 2.46 Å. The Fe–C bond length is 1.84 Å. In the ninth Fe site, Fe is bonded in a single-bond geometry to six Fe and one N atom. The Fe–Fe bond length is 2.49 Å. The Fe–N bond length is 1.88 Å. In the tenth Fe site, Fe is bonded to two equivalent Y and ten Fe atoms to form distorted FeY2Fe10 cuboctahedra that share corners with eight FeY3Fe9 cuboctahedra, corners with two equivalent CY2Fe4 octahedra, corners with two equivalent NY2Fe4 octahedra, edges with three FeY2Fe10 cuboctahedra, an edgeedge with one CY2Fe4 octahedra, an edgeedge with one NY2Fe4 octahedra, and faces with nine FeY3Fe9 cuboctahedra. The corner-sharing octahedra tilt angles range from 23–29°. C is bonded to two equivalent Y and four Fe atoms to form CY2Fe4 octahedra that share corners with ten FeY3Fe9 cuboctahedra, corners with two equivalent NY2Fe4 octahedra, edges with two equivalent FeY2Fe10 cuboctahedra, and faces with six FeY2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 62°. N is bonded to two equivalent Y and four Fe atoms to form NY2Fe4 octahedra that share corners with ten FeY3Fe9 cuboctahedra, corners with two equivalent CY2Fe4 octahedra, edges with two equivalent FeY2Fe10 cuboctahedra, and faces with six FeY2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 62°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg14FeW by Materials Project

Mg14WFe crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are seven inequivalent Mg sites. In the first Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent WMg10Fe2 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with six MgMg12 cuboctahedra, faces with two equivalent FeMg10W2 cuboctahedra, and faces with six MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.00–3.20 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent FeMg10W2 cuboctahedra, corners with fourteen MgMg12 cuboctahedra, edges with six MgMg12 cuboctahedra, faces with two equivalent WMg10Fe2 cuboctahedra, and faces with six MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.07–3.20 Å. In the third Mg site, Mg is bonded to eight Mg, two equivalent W, and two equivalent Fe atoms to form distorted MgMg8Fe2W2 cuboctahedra that share corners with eighteen MgMg12 cuboctahedra, edges with two equivalent MgMg8Fe2W2 cuboctahedra, edges with two equivalent WMg10Fe2 cuboctahedra, edges with two equivalent FeMg10W2 cuboctahedra, faces with two equivalent WMg10Fe2 cuboctahedra, faces with two equivalent FeMg10W2 cuboctahedra, and faces with four MgMg8Fe2W2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.91–3.03 Å. There are one shorter (3.03 Å) and one longer (3.21 Å) Mg–W bond lengths. There are one shorter (3.10 Å) and one longer (3.14 Å) Mg–Fe bond lengths. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent WMg10Fe2 cuboctahedra, corners with four equivalent FeMg10W2 cuboctahedra, corners with ten MgMg8Fe2W2 cuboctahedra, edges with six MgMg12 cuboctahedra, and faces with eight MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.99–3.25 Å. In the fifth Mg site, Mg is bonded in a 12-coordinate geometry to four Mg, one W, and one Fe atom. The Mg–W bond length is 2.90 Å. The Mg–Fe bond length is 2.87 Å. In the sixth Mg site, Mg is bonded in a distorted single-bond geometry to five Mg and one Fe atom. The Mg–Fe bond length is 2.86 Å. In the seventh Mg site, Mg is bonded in a distorted single-bond geometry to five Mg and one W atom. The Mg–W bond length is 2.92 Å. W is bonded to ten Mg and two equivalent Fe atoms to form WMg10Fe2 cuboctahedra that share corners with six equivalent WMg10Fe2 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent FeMg10W2 cuboctahedra, edges with four equivalent MgMg8Fe2W2 cuboctahedra, faces with two equivalent FeMg10W2 cuboctahedra, and faces with six MgMg12 cuboctahedra. Both W–Fe bond lengths are 3.00 Å. Fe is bonded to ten Mg and two equivalent W atoms to form FeMg10W2 cuboctahedra that share corners with six equivalent FeMg10W2 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent WMg10Fe2 cuboctahedra, edges with four equivalent MgMg8Fe2W2 cuboctahedra, faces with two equivalent WMg10Fe2 cuboctahedra, and faces with six MgMg12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Mechanistic insight into the active centers of single/dual-atom Ni/Fe-based oxygen electrocatalysts

Single-atom catalysts with maximum metal utilization efficiency show great potential for sustainable catalytic applications and fundamental mechanistic studies. We here provide a convenient molecular tailoring strategy based on graphitic carbon nitride as support for the rational design of single-site and dual-site single-atom catalysts. Catalysts with single Fe sites exhibit impressive oxygen reduction reaction activity with a half-wave potential of 0.89 V vs. RHE. We find that the single Ni sites are favorable to promote the key structural reconstruction into bridging Ni-O-Fe bonds in dual-site NiFe SAC. Meanwhile, the newly formed Ni-O-Fe bonds create spin channels for electron transfer, resulting in a significant improvement of the oxygen evolution reaction activity with an overpotential of 270 mV at 10 mA cm –2 . We further reveal that the water oxidation reaction follows a dual-site pathway through the deprotonation of *OH at both Ni and Fe sites, leading to the formation of bridging O 2 atop the Ni-O-Fe sites.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on Sm4CrFe33C4 by Materials Project

Sm4CrFe33C4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Sm sites. In the first Sm site, Sm is bonded in a distorted bent 120 degrees geometry to eight Fe and two C atoms. There are a spread of Sm–Fe bond distances ranging from 3.06–3.40 Å. Both Sm–C bond lengths are 2.54 Å. In the second Sm site, Sm is bonded in a distorted bent 120 degrees geometry to nine Fe and two C atoms. There are a spread of Sm–Fe bond distances ranging from 3.05–3.39 Å. There are one shorter (2.54 Å) and one longer (2.55 Å) Sm–C bond lengths. In the third Sm site, Sm is bonded in a distorted bent 120 degrees geometry to nine Fe and two C atoms. There are a spread of Sm–Fe bond distances ranging from 3.05–3.40 Å. There are one shorter (2.54 Å) and one longer (2.55 Å) Sm–C bond lengths. In the fourth Sm site, Sm is bonded in a distorted bent 120 degrees geometry to one Cr, eight Fe, and two C atoms. The Sm–Cr bond length is 3.20 Å. There are a spread of Sm–Fe bond distances ranging from 3.01–3.43 Å. There are one shorter (2.54 Å) and one longer (2.55 Å) Sm–C bond lengths. Cr is bonded in a 1-coordinate geometry to one Sm and thirteen Fe atoms. There are a spread of Cr–Fe bond distances ranging from 2.31–2.75 Å. There are thirty-three inequivalent Fe sites. In the first Fe site, Fe is bonded to three Sm and nine Fe atoms to form distorted FeSm3Fe9 cuboctahedra that share corners with eleven FeSm3Fe9 cuboctahedra, corners with four CSm2Fe4 octahedra, edges with four FeSm2Fe10 cuboctahedra, faces with eight FeSm2Fe10 cuboctahedra, and faces with two CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 63–69°. There are a spread of Fe–Fe bond distances ranging from 2.47–2.69 Å. In the second Fe site, Fe is bonded to three Sm, one Cr, and eight Fe atoms to form distorted FeSm3CrFe8 cuboctahedra that share corners with eleven FeSm3CrFe8 cuboctahedra, corners with four CSm2Fe4 octahedra, edges with four FeSm2Fe10 cuboctahedra, faces with eight FeSm2CrFe9 cuboctahedra, and faces with two CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 63–71°. There are a spread of Fe–Fe bond distances ranging from 2.46–2.68 Å. In the third Fe site, Fe is bonded in a single-bond geometry to one Cr, four Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.46–2.56 Å. The Fe–C bond length is 1.92 Å. In the fourth Fe site, Fe is bonded in a single-bond geometry to five Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.46–2.65 Å. The Fe–C bond length is 1.91 Å. In the fifth Fe site, Fe is bonded in a single-bond geometry to five Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.47–2.65 Å. The Fe–C bond length is 1.92 Å. In the sixth Fe site, Fe is bonded in a single-bond geometry to one Cr, four Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.46–2.56 Å. The Fe–C bond length is 1.92 Å. In the seventh Fe site, Fe is bonded to three Sm and nine Fe atoms to form distorted FeSm3Fe9 cuboctahedra that share corners with eleven FeSm3Fe9 cuboctahedra, corners with four CSm2Fe4 octahedra, edges with four FeSm2Fe10 cuboctahedra, faces with eight FeSm2CrFe9 cuboctahedra, and faces with two CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 63–69°. There are a spread of Fe–Fe bond distances ranging from 2.47–2.69 Å. In the eighth Fe site, Fe is bonded to three Sm and nine Fe atoms to form distorted FeSm3Fe9 cuboctahedra that share corners with eleven FeSm3Fe9 cuboctahedra, corners with four CSm2Fe4 octahedra, edges with four FeSm2Fe10 cuboctahedra, faces with eight FeSm2Fe10 cuboctahedra, and faces with two CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 62–69°. There are a spread of Fe–Fe bond distances ranging from 2.48–2.68 Å. In the ninth Fe site, Fe is bonded in a single-bond geometry to five Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.47–2.64 Å. The Fe–C bond length is 1.91 Å. In the tenth Fe site, Fe is bonded in a single-bond geometry to four Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.45–2.56 Å. The Fe–C bond length is 1.92 Å. In the eleventh Fe site, Fe is bonded in a single-bond geometry to four Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.46–2.56 Å. The Fe–C bond length is 1.91 Å. In the twelfth Fe site, Fe is bonded in a single-bond geometry to five Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.46–2.65 Å. The Fe–C bond length is 1.92 Å. In the thirteenth Fe site, Fe is bonded in a single-bond geometry to one Cr, four Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.43–2.46 Å. The Fe–C bond length is 1.85 Å. In the fourteenth Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.43–2.74 Å. The Fe–C bond length is 1.86 Å. In the fifteenth Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.45–2.75 Å. The Fe–C bond length is 1.86 Å. In the sixteenth Fe site, Fe is bonded in a single-bond geometry to one Cr, four Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.43–2.49 Å. The Fe–C bond length is 1.86 Å. In the seventeenth Fe site, Fe is bonded to two Sm, one Cr, and nine Fe atoms to form distorted FeSm2CrFe9 cuboctahedra that share corners with eight FeSm3Fe9 cuboctahedra, corners with four CSm2Fe4 octahedra, edges with three FeSm2Fe10 cuboctahedra, edges with two CSm2Fe4 octahedra, and faces with nine FeSm2CrFe9 cuboctahedra. The corner-sharing octahedra tilt angles range from 21–29°. There are a spread of Fe–Fe bond distances ranging from 2.44–2.68 Å. In the eighteenth Fe site, Fe is bonded to two Sm and ten Fe atoms to form distorted FeSm2Fe10 cuboctahedra that share corners with eight FeSm2Fe10 cuboctahedra, corners with four CSm2Fe4 octahedra, edges with three FeSm2Fe10 cuboctahedra, edges with two CSm2Fe4 octahedra, and faces with nine FeSm2Fe10 cuboctahedra. The corner-sharing octahedra tilt angles range from 21–29°. There are a spread of Fe–Fe bond distances ranging from 2.43–2.74 Å. In the nineteenth Fe site, Fe is bonded in a single-bond geometry to one Cr, four Fe, and one C atom. There are one shorter (2.43 Å) and one longer (2.45 Å) Fe–Fe bond lengths. The Fe–C bond length is 1.85 Å. In the twentieth Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.44–2.75 Å. The Fe–C bond length is 1.86 Å. In the twenty-first Fe site, Fe is bonded to two Sm and ten Fe atoms to form distorted FeSm2Fe10 cuboctahedra that share corners with eight FeSm2Fe10 cuboctahedra, corners with four CSm2Fe4 octahedra, edges with three FeSm2Fe10 cuboctahedra, edges with two CSm2Fe4 octahedra, and faces with nine FeSm2Fe10 cuboctahedra. The corner-sharing octahedra tilt angles range from 21–29°. There are a spread of Fe–Fe bond distances ranging from 2.43–2.72 Å. In the twenty-second Fe site, Fe is bonded to two Sm, one Cr, and nine Fe atoms to form distorted FeSm2CrFe9 cuboctahedra that share corners with eight FeSm3CrFe8 cuboctahedra, corners with four CSm2Fe4 octahedra, edges with three FeSm2Fe10 cuboctahedra, edges with two CSm2Fe4 octahedra, and faces with nine FeSm2CrFe9 cuboctahedra. The corner-sharing octahedra tilt angles range from 22–28°. There are a spread of Fe–Fe bond distances ranging from 2.43–2.72 Å. In the twenty-third Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.43–2.75 Å. The Fe–C bond length is 1.86 Å. In the twenty-fourth Fe site, Fe is bonded in a single-bond geometry to one Cr, four Fe, and one C atom. There are one shorter (2.43 Å) and one longer (2.45 Å) Fe–Fe bond lengths. The Fe–C bond length is 1.85 Å. In the twenty-fifth Fe site, Fe is bonded to two Sm and ten Fe atoms to form FeSm2Fe10 cuboctahedra that share corners with eight FeSm2Fe10 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with four FeSm3Fe9 cuboctahedra, faces with eight FeSm2Fe10 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The corner-sharing octahedral tilt angles are 45°. There are one shorter (2.65 Å) and one longer (2.66 Å) Fe–Fe bond lengths. In the twenty-sixth Fe site, Fe is bonded to two Sm, one Cr, and nine Fe atoms to form distorted FeSm2CrFe9 cuboctahedra that share corners with eight FeSm2Fe10 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with four FeSm3CrFe8 cuboctahedra, faces with eight FeSm2Fe10 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 45–48°. The Fe–Fe bond length is 2.67 Å. In the twenty-seventh Fe site, Fe is bonded to two Sm, one Cr, and nine Fe atoms to form distorted FeSm2CrFe9 cuboctahedra that share corners with eight FeSm2CrFe9 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with four FeSm3Fe9 cuboctahedra, faces with eight FeSm2CrFe9 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 45–48°. The Fe–Fe bond length is 2.68 Å. In the twenty-eighth Fe site, Fe is bonded to two Sm and ten Fe atoms to form FeSm2Fe10 cuboctahedra that share corners with eight FeSm2Fe10 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with four FeSm3CrFe8 cuboctahedra, faces with eight FeSm2Fe10 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The corner-sharing octahedral tilt angles are 45°. There are one shorter (2.64 Å) and one longer (2.65 Å) Fe–Fe bond lengths. In the twenty-ninth Fe site, Fe is bonded to two Sm and ten Fe atoms to form distorted FeSm2Fe10 cuboctahedra that share corners with fourteen FeSm3Fe9 cuboctahedra, edges with two FeSm3Fe9 cuboctahedra, faces with ten FeSm2Fe10 cuboctahedra, and faces with four CSm2Fe4 octahedra. Both Fe–Fe bond lengths are 2.65 Å. In the thirtieth Fe site, Fe is bonded to two Sm, one Cr, and nine Fe atoms to form distorted FeSm2CrFe9 cuboctahedra that share corners with fourteen FeSm3Fe9 cuboctahedra, edges with two FeSm3Fe9 cuboctahedra, faces with ten FeSm3CrFe8 cuboctahedra, and faces with four CSm2Fe4 octahedra. The Fe–Fe bond length is 2.69 Å. In the thirty-first Fe site, Fe is bonded in a distorted single-bond geometry to one Cr and six Fe atoms. In the thirty-second Fe site, Fe is bonded in a 2-coordinate geometry to one Sm and thirteen Fe atoms. The Fe–Fe bond length is 2.38 Å. In the thirty-third Fe site, Fe is bonded in a 2-coordinate geometry to one Sm and thirteen Fe atoms. There are four inequivalent C sites. In the first C site, C is bonded to two Sm and four Fe atoms to form CSm2Fe4 octahedra that share corners with ten FeSm3CrFe8 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with two FeSm2Fe10 cuboctahedra, and faces with six FeSm2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 63°. In the second C site, C is bonded to two Sm and four Fe atoms to form CSm2Fe4 octahedra that share corners with ten FeSm3Fe9 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with two FeSm2CrFe9 cuboctahedra, and faces with six FeSm2CrFe9 cuboctahedra. The corner-sharing octahedra tilt angles range from 63–64°. In the third C site, C is bonded to two Sm and four Fe atoms to form CSm2Fe4 octahedra that share corners with ten FeSm2Fe10 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with two FeSm2Fe10 cuboctahedra, and faces with six FeSm2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 63°. In the fourth C site, C is bonded to two Sm and four Fe atoms to form CSm2Fe4 octahedra that share corners with ten FeSm2Fe10 cuboctahedra, corners with two CSm2Fe4 octahedra, edges with two FeSm2CrFe9 cuboctahedr

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on YVFe11H by Materials Project

YVFe11H crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. Y is bonded in a distorted linear geometry to one V, ten Fe, and two equivalent H atoms. The Y–V bond length is 3.17 Å. There are a spread of Y–Fe bond distances ranging from 3.04–3.24 Å. Both Y–H bond lengths are 2.36 Å. V is bonded in a 1-coordinate geometry to one Y and thirteen Fe atoms. There are a spread of V–Fe bond distances ranging from 2.26–2.87 Å. There are six inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to six Fe and one H atom. There are four shorter (2.43 Å) and two longer (2.59 Å) Fe–Fe bond lengths. The Fe–H bond length is 1.92 Å. In the second Fe site, Fe is bonded in a distorted single-bond geometry to two equivalent V, six Fe, and one H atom. There are four shorter (2.42 Å) and two longer (2.60 Å) Fe–Fe bond lengths. The Fe–H bond length is 1.94 Å. In the third Fe site, Fe is bonded in a single-bond geometry to one V, six Fe, and one H atom. There are a spread of Fe–Fe bond distances ranging from 2.42–2.62 Å. The Fe–H bond length is 1.90 Å. In the fourth Fe site, Fe is bonded to two equivalent Y, one V, and nine Fe atoms to form distorted FeY2VFe9 cuboctahedra that share corners with ten equivalent FeY2VFe9 cuboctahedra, corners with two equivalent HY2Fe4 octahedra, edges with four equivalent FeY2VFe9 cuboctahedra, faces with six equivalent FeY2VFe9 cuboctahedra, and faces with two equivalent HY2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 68–69°. There are a spread of Fe–Fe bond distances ranging from 2.36–2.60 Å. In the fifth Fe site, Fe is bonded in a distorted single-bond geometry to one V and eight Fe atoms. All Fe–Fe bond lengths are 2.88 Å. In the sixth Fe site, Fe is bonded in a 12-coordinate geometry to one Y, two equivalent V, and eleven Fe atoms. The Fe–Fe bond length is 2.38 Å. H is bonded to two equivalent Y and four Fe atoms to form HY2Fe4 octahedra that share corners with eight equivalent FeY2VFe9 cuboctahedra, corners with two equivalent HY2Fe4 octahedra, and faces with eight equivalent FeY2VFe9 cuboctahedra. The corner-sharing octahedral tilt angles are 2°.

36 MATERIALS SCIENCE↗