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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Rb2Pd(IBr2)2 by Materials Project

Rb2Pd(IBr2)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Rb1+ is bonded in a 8-coordinate geometry to eight equivalent Br1- atoms. All Rb–Br bond lengths are 3.80 Å. Pd4+ is bonded in an octahedral geometry to two equivalent I1- and four equivalent Br1- atoms. Both Pd–I bond lengths are 3.06 Å. All Pd–Br bond lengths are 2.48 Å. I1- is bonded in a 1-coordinate geometry to one Pd4+ atom. Br1- is bonded in a distorted single-bond geometry to four equivalent Rb1+ and one Pd4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PdC9N3Cl5 by Materials Project

PdC6(NCl2)2ClC1C2N crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of four 2-chloro-1-methylaziridine molecules and four PdC6(NCl2)2 clusters. In each PdC6(NCl2)2 cluster, Pd2+ is bonded in a rectangular see-saw-like geometry to four Cl1- atoms. There are two shorter (2.30 Å) and two longer (2.42 Å) Pd–Cl bond lengths. There are three inequivalent C+1.33+ sites. In the first C+1.33+ site, C+1.33+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.20 Å. In the second C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one C+1.33+ and one N3- atom. The C–C bond length is 1.22 Å. The C–N bond length is 1.29 Å. In the third C+1.33+ site, C+1.33+ is bonded in a distorted single-bond geometry to one C+1.33+ and one Cl1- atom. The C–Cl bond length is 1.63 Å. N3- is bonded in a linear geometry to two C+1.33+ atoms. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Pd2+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Pd2+ atom. In the third Cl1- site, Cl1- is bonded in a water-like geometry to one Pd2+ and one C+1.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Finite-Temperature Structures of Supported Subnanometer Catalysts Inferred via Statistical Learning and Genetic Algorithm-Based Optimization

Single-atom catalysts (SACs) minimize noble metal utilization and can alter the activity and selectivity of supported metal nanoparticles. However, the morphology of active centers, including single atoms and subnanometer clusters of a few atoms, remains elusive due to experimental challenges. The computational cost to describe numerous cluster shapes and sizes makes direct first-principles calculations impractical. We present a computational framework to enable structure determination for single-atom and subnanometer cluster catalysts. As a case study, we obtained the low energy structures of Pd n (n = 1-21) clusters supported on CeO 2 (111), which are critical components of automobile three-way catalysts. Trained on density functional theory data, a three-dimensional cluster expansion is established using statistical learning to describe the Hamiltonian and predict energies of supported Pdn clusters of any structure. Low energy stable and metastable structures are identified using a Metropolis Monte Carlo-based genetic algorithm in the canonical ensemble at 300 K. We observe that supported single atoms sinter to form bilayer clusters and large cluster isomers share similarities in both shape and energy, and elucidate the significance of the support and microstructure on cluster stability. We discovered a simple surrogate structure-energy model, where the energy per atom scales with the square root of the average first coordination number, which can be used to estimate energies and compare the stability of clusters. Our framework, applicable to any metal/support system, fills an important methodological gap to predict the stability of supported metal catalysts in the subnanometer regime.

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

Observation of nanoparticle coalescence during core-shell metallic nanowire growth in colloids via nanoscale imaging

The surface morphology and shape of crystalline nanowires significantly influence their functional properties, including phonon transport, electrocatalytic performance, to name but a few. However, the kinetic pathways driving these morphological changes remain underexplored due to challenges in real-space and real-time imaging at single-particle and atomic resolutions. This study investigates the dynamics of shell (Au, Pd, Pt, Fe, Cu, Ni) deposition on AuAg alloy seed nanowires during core-shell formation. By using chiral/non-chiral seed nanowires, advanced imaging techniques, including liquid-phase transmission electron microscopy (LPTEM), cryogenic TEM, and three-dimensional electron tomography, a three-step deposition process is revealed: heterogeneous nucleation, nanoparticle attachment, and coalescence. It is found that colloidal Ostwald ripening, metal reactivity, and deposition amount modulate nanoparticle size and surface roughness, shaping final morphologies. Noble metal nanoparticles (Au, Ag, Pd, Pt) coalesce with seed nanowire along the 〈111〉 direction, distinct from that of other metals. These findings are consistent across different metals, including Ru, Cu, Fe, and Ni, highlighting the hypothesis of these processes in nanowire formation. These findings enhance traditional crystallographic theories and provide a framework for designing nanowire morphology. Additionally, our imaging techniques may be applied to investigate phenomena like electrodeposition, dendrite growth in batteries, and membrane deformation.

Yang, Dahai↗
DOE OSTI2020

Materials Data on Al2PdCl8 by Materials Project

PdAl2Cl8 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two PdAl2Cl8 clusters. Pd2+ is bonded in a square co-planar geometry to four Cl1- atoms. All Pd–Cl bond lengths are 2.34 Å. Al3+ is bonded in a tetrahedral geometry to four Cl1- atoms. There are a spread of Al–Cl bond distances ranging from 2.10–2.25 Å. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In the second Cl1- site, Cl1- is bonded in an L-shaped geometry to one Pd2+ and one Al3+ atom. In the third Cl1- site, Cl1- is bonded in an L-shaped geometry to one Pd2+ and one Al3+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pd(SeBr3)2 by Materials Project

Pd(SeBr3)2 crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of one Pd(SeBr3)2 ribbon oriented in the (1, 0, 0) direction. Pd4+ is bonded in a distorted square co-planar geometry to two equivalent Se2- and two equivalent Br atoms. Both Pd–Se bond lengths are 2.44 Å. Both Pd–Br bond lengths are 2.47 Å. Se2- is bonded in a 5-coordinate geometry to one Pd4+ and four Br atoms. There are a spread of Se–Br bond distances ranging from 2.37–3.14 Å. There are three inequivalent Br sites. In the first Br site, Br is bonded in a 1-coordinate geometry to one Pd4+ and two equivalent Se2- atoms. In the second Br site, Br is bonded in a single-bond geometry to one Se2- atom. In the third Br site, Br is bonded in a single-bond geometry to one Se2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PdF4 by Materials Project

PdF4 crystallizes in the orthorhombic Fdd2 space group. The structure is three-dimensional. Pd4+ is bonded to six F1- atoms to form corner-sharing PdF6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Pd–F bond distances ranging from 1.88–2.06 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Pd4+ atom. In the second F1- site, F1- is bonded in a bent 120 degrees geometry to two equivalent Pd4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ga2PdBr8 by Materials Project

PdGa2Br8 crystallizes in the monoclinic C2/m space group. The structure is zero-dimensional and consists of two PdGa2Br8 clusters. Pd2+ is bonded in a square co-planar geometry to four equivalent Br1- atoms. All Pd–Br bond lengths are 2.47 Å. Ga3+ is bonded in a tetrahedral geometry to four Br1- atoms. There are a spread of Ga–Br bond distances ranging from 2.29–2.46 Å. There are three inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in an L-shaped geometry to one Pd2+ and one Ga3+ atom. In the second Br1- site, Br1- is bonded in a single-bond geometry to one Ga3+ atom. In the third Br1- site, Br1- is bonded in a single-bond geometry to one Ga3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2Pd(CN)4 by Materials Project

K2Pd(CN)4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to six N3- atoms. There are a spread of K–N bond distances ranging from 2.83–3.34 Å. Pd2+ is bonded in a square co-planar geometry to four C2+ atoms. There is two shorter (1.99 Å) and two longer (2.00 Å) Pd–C bond length. There are two inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a distorted single-bond geometry to one Pd2+ and one N3- atom. The C–N bond length is 1.18 Å. In the second C2+ site, C2+ is bonded in a distorted single-bond geometry to one Pd2+ and one N3- atom. The C–N bond length is 1.17 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a 1-coordinate geometry to three equivalent K1+ and one C2+ atom. In the second N3- site, N3- is bonded in a 1-coordinate geometry to three equivalent K1+ and one C2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CeSb2Pd by Materials Project

CePdSb2 crystallizes in the tetragonal P4/mmm space group. The structure is one-dimensional and consists of one CePdSb2 ribbon oriented in the (0, 0, 1) direction. Ce3+ is bonded in a linear geometry to one Pd2+ and one Sb+2.50- atom. The Ce–Pd bond length is 2.29 Å. The Ce–Sb bond length is 2.80 Å. Pd2+ is bonded in a linear geometry to one Ce3+ and one Sb+2.50- atom. The Pd–Sb bond length is 2.52 Å. There are three inequivalent Sb+2.50- sites. In the first Sb+2.50- site, Sb+2.50- is bonded in a distorted single-bond geometry to one Ce3+ and one Sb+2.50- atom. The Sb–Sb bond length is 2.71 Å. In the second Sb+2.50- site, Sb+2.50- is bonded in a linear geometry to two equivalent Sb+2.50- atoms. In the third Sb+2.50- site, Sb+2.50- is bonded in a linear geometry to two equivalent Pd2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pd(NCl)2 by Materials Project

Pd(NCl)2 crystallizes in the triclinic P1 space group. The structure is one-dimensional and consists of one Pd(NCl)2 ribbon oriented in the (1, 0, 0) direction. Pd2+ is bonded in a distorted rectangular see-saw-like geometry to four N atoms. There are three shorter (2.01 Å) and one longer (2.02 Å) Pd–N bond lengths. There are two inequivalent N sites. In the first N site, N is bonded in a trigonal planar geometry to two equivalent Pd2+ and one Cl1- atom. The N–Cl bond length is 1.66 Å. In the second N site, N is bonded in a trigonal planar geometry to two equivalent Pd2+ and one Cl1- atom. The N–Cl bond length is 1.66 Å. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one N atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Enhancing the activity of Pd ensembles on graphene by manipulating coordination environment

Atomic dispersion of metal catalysts on a substrate accounts for the increased atomic efficiency of single-atom catalysts (SACs) in various catalytic schemes compared to the nanoparticle counterparts. However, lacking neighboring metal sites has been shown to deteriorate the catalytic performance of SACs in a few industrially important reactions, such as dehalogenation, CO oxidation, and hydrogenation. Metal ensemble catalysts (M n ), an extended concept to SACs, have emerged as a promising alternative to overcome such limitation. Inspired by the fact that the performance of fully isolated SACs can be enhanced by tailoring their coordination environment (CE), we here evaluate whether the CE of M n can also be manipulated in order to enhance their catalytic activity. We synthesized a set of Pd ensembles (Pd n ) on doped graphene supports (Pd n /X-graphene where X = O, S, B, and N). We found that introducing S and N onto oxidized graphene modifies the first shell of Pd n converting Pd–O to Pd–S and Pd–N, respectively. Also, we further found that the B dopant significantly affected the electronic structure of Pd n by serving as an electron donor in the second shell. We examined the performance of Pd n /X-graphene toward selective reductive catalysis, such as bromate reduction, brominated organic hydrogenation, and aqueous-phase CO 2 reduction. We observed that Pd n /N-graphene exhibited superior performance by lowering the activation energy of the rate-limiting step, i.e., H 2 dissociation into atomic hydrogen. The results collectively suggest controlling the CE of SACs in an ensemble configuration is a viable strategy to optimize and enhance their catalytic performance.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Single-Atom Alloy Formation via Reaction-Driven Catalyst Restructuring

We demonstrate that single-atom alloy catalysts can be made by exposing physical mixtures of monometallic supported Cu and Pd catalysts to vinyl acetate (VA) synthesis reaction conditions. This reaction induces the formation of mobile clusters of metal diacetate species that drive extensive metal nanoparticle restructuring, leading to atomic dispersion of the precious metal, smaller nanoparticle sizes than the parent catalysts, and high activity and selectivity for both VA synthesis and ethanol dehydrogenation reactions. As a result, this approach is scalable and appears to be generalizable to other alloy catalysts.

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

Materials Data on TePdI2 by Materials Project

PdTeI2 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one PdTeI2 sheet oriented in the (0, 0, 1) direction. Pd4+ is bonded to three equivalent Te2- and three equivalent I1- atoms to form distorted edge-sharing PdTe3I3 octahedra. There are a spread of Pd–Te bond distances ranging from 2.62–3.12 Å. There are a spread of Pd–I bond distances ranging from 2.73–3.48 Å. Te2- is bonded in a 3-coordinate geometry to three equivalent Pd4+ and one I1- atom. The Te–I bond length is 2.82 Å. There are two inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted L-shaped geometry to three equivalent Pd4+ atoms. In the second I1- site, I1- is bonded in a distorted single-bond geometry to one Te2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sb2Te4Pd3 by Materials Project

Pd3Sb2Te4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twelve inequivalent Pd2+ sites. In the first Pd2+ site, Pd2+ is bonded in a see-saw-like geometry to four Te2- atoms. There are a spread of Pd–Te bond distances ranging from 2.73–2.78 Å. In the second Pd2+ site, Pd2+ is bonded in a see-saw-like geometry to four Te2- atoms. There are a spread of Pd–Te bond distances ranging from 2.74–2.78 Å. In the third Pd2+ site, Pd2+ is bonded to five Te2- atoms to form corner-sharing PdTe5 square pyramids. There are a spread of Pd–Te bond distances ranging from 2.73–2.80 Å. In the fourth Pd2+ site, Pd2+ is bonded in a see-saw-like geometry to four Te2- atoms. There are a spread of Pd–Te bond distances ranging from 2.74–2.78 Å. In the fifth Pd2+ site, Pd2+ is bonded in a see-saw-like geometry to four Te2- atoms. There are a spread of Pd–Te bond distances ranging from 2.74–2.79 Å. In the sixth Pd2+ site, Pd2+ is bonded to five Te2- atoms to form corner-sharing PdTe5 square pyramids. There are a spread of Pd–Te bond distances ranging from 2.74–2.79 Å. In the seventh Pd2+ site, Pd2+ is bonded in a see-saw-like geometry to four Te2- atoms. There are a spread of Pd–Te bond distances ranging from 2.74–2.79 Å. In the eighth Pd2+ site, Pd2+ is bonded in a see-saw-like geometry to four Te2- atoms. There are a spread of Pd–Te bond distances ranging from 2.73–2.79 Å. In the ninth Pd2+ site, Pd2+ is bonded in a rectangular see-saw-like geometry to four Te2- atoms. There are a spread of Pd–Te bond distances ranging from 2.73–2.79 Å. In the tenth Pd2+ site, Pd2+ is bonded in a rectangular see-saw-like geometry to four Te2- atoms. There are a spread of Pd–Te bond distances ranging from 2.74–2.79 Å. In the eleventh Pd2+ site, Pd2+ is bonded in a 3-coordinate geometry to three Te2- atoms. There are one shorter (2.77 Å) and two longer (2.78 Å) Pd–Te bond lengths. In the twelfth Pd2+ site, Pd2+ is bonded in a distorted T-shaped geometry to three Te2- atoms. There are one shorter (2.77 Å) and two longer (2.78 Å) Pd–Te bond lengths. There are eight inequivalent Sb1+ sites. In the first Sb1+ site, Sb1+ is bonded in a single-bond geometry to one Te2- atom. The Sb–Te bond length is 2.92 Å. In the second Sb1+ site, Sb1+ is bonded in a single-bond geometry to one Te2- atom. The Sb–Te bond length is 2.91 Å. In the third Sb1+ site, Sb1+ is bonded in a single-bond geometry to one Te2- atom. The Sb–Te bond length is 2.92 Å. In the fourth Sb1+ site, Sb1+ is bonded in a single-bond geometry to one Te2- atom. The Sb–Te bond length is 2.92 Å. In the fifth Sb1+ site, Sb1+ is bonded in a single-bond geometry to one Te2- atom. The Sb–Te bond length is 2.92 Å. In the sixth Sb1+ site, Sb1+ is bonded in a single-bond geometry to one Te2- atom. The Sb–Te bond length is 2.91 Å. In the seventh Sb1+ site, Sb1+ is bonded in a single-bond geometry to one Te2- atom. The Sb–Te bond length is 2.93 Å. In the eighth Sb1+ site, Sb1+ is bonded in a single-bond geometry to one Te2- atom. The Sb–Te bond length is 2.92 Å. There are sixteen inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 4-coordinate geometry to three Pd2+ and one Te2- atom. The Te–Te bond length is 2.97 Å. In the second Te2- site, Te2- is bonded in a 4-coordinate geometry to three Pd2+ and one Te2- atom. The Te–Te bond length is 2.98 Å. In the third Te2- site, Te2- is bonded in a 4-coordinate geometry to three Pd2+ and one Te2- atom. The Te–Te bond length is 2.99 Å. In the fourth Te2- site, Te2- is bonded in a 4-coordinate geometry to three Pd2+ and one Te2- atom. The Te–Te bond length is 3.00 Å. In the fifth Te2- site, Te2- is bonded to three Pd2+ and one Sb1+ atom to form distorted corner-sharing TeSbPd3 trigonal pyramids. In the sixth Te2- site, Te2- is bonded to three Pd2+ and one Sb1+ atom to form distorted corner-sharing TeSbPd3 trigonal pyramids. In the seventh Te2- site, Te2- is bonded to three Pd2+ and one Sb1+ atom to form distorted corner-sharing TeSbPd3 trigonal pyramids. In the eighth Te2- site, Te2- is bonded to three Pd2+ and one Sb1+ atom to form distorted corner-sharing TeSbPd3 trigonal pyramids. In the ninth Te2- site, Te2- is bonded to three Pd2+ and one Sb1+ atom to form distorted corner-sharing TeSbPd3 trigonal pyramids. In the tenth Te2- site, Te2- is bonded to three Pd2+ and one Sb1+ atom to form distorted corner-sharing TeSbPd3 trigonal pyramids. In the eleventh Te2- site, Te2- is bonded to three Pd2+ and one Sb1+ atom to form distorted corner-sharing TeSbPd3 trigonal pyramids. In the twelfth Te2- site, Te2- is bonded to three Pd2+ and one Sb1+ atom to form distorted corner-sharing TeSbPd3 tetrahedra. In the thirteenth Te2- site, Te2- is bonded in a 4-coordinate geometry to three Pd2+ and one Te2- atom. In the fourteenth Te2- site, Te2- is bonded in a 4-coordinate geometry to three Pd2+ and one Te2- atom. In the fifteenth Te2- site, Te2- is bonded in a 4-coordinate geometry to three Pd2+ and one Te2- atom. In the sixteenth Te2- site, Te2- is bonded in a 4-coordinate geometry to three Pd2+ and one Te2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pd(NCl)2 by Materials Project

Pd(NCl)2 crystallizes in the triclinic P1 space group. The structure is one-dimensional and consists of one Pd(NCl)2 ribbon oriented in the (0, 1, 0) direction. Pd2+ is bonded in a 3-coordinate geometry to two N and one Cl1- atom. There is one shorter (1.83 Å) and one longer (1.89 Å) Pd–N bond length. The Pd–Cl bond length is 2.56 Å. There are two inequivalent N sites. In the first N site, N is bonded in a bent 150 degrees geometry to one Pd2+ and one Cl1- atom. The N–Cl bond length is 1.63 Å. In the second N site, N is bonded in a distorted bent 120 degrees geometry to one Pd2+ and one Cl1- atom. The N–Cl bond length is 1.65 Å. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted bent 120 degrees geometry to one Pd2+ and one N atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on P2Pd3S8 by Materials Project

Pd3(PS4)2 crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one Pd3(PS4)2 sheet oriented in the (0, 0, 1) direction. Pd2+ is bonded in a square co-planar geometry to four equivalent S2- atoms. All Pd–S bond lengths are 2.36 Å. P5+ is bonded in a distorted tetrahedral geometry to four S2- atoms. There are one shorter (1.91 Å) and three longer (2.13 Å) P–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to two equivalent Pd2+ and one P5+ atom. In the second S2- site, S2- is bonded in a single-bond geometry to one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CrH12Pd(NO)4 by Materials Project

CrO4PdN4H12 crystallizes in the tetragonal I4_1/amd space group. The structure is zero-dimensional and consists of four cq4 molecules and four PdN4H12 clusters. In each PdN4H12 cluster, Pd2+ is bonded in a rectangular see-saw-like geometry to four equivalent N3- atoms. All Pd–N bond lengths are 2.06 Å. N3- is bonded in a distorted trigonal non-coplanar geometry to one Pd2+ and three H1+ atoms. There is two shorter (1.03 Å) and one longer (1.04 Å) N–H bond length. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom.

36 MATERIALS SCIENCE↗