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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Li3P11(H3N)17 by Materials Project

(Li(NH3)4)3(P)11(NH3)5 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of ten ammonia molecules, six Li(NH3)4 clusters, and two P clusters. In two of the Li(NH3)4 clusters, Li is bonded in a tetrahedral geometry to four N atoms. There are a spread of Li–N bond distances ranging from 2.04–2.10 Å. There are four inequivalent N sites. In the first N site, N is bonded to one Li and three H atoms to form distorted corner-sharing NLiH3 tetrahedra. All N–H bond lengths are 1.03 Å. In the second N site, N is bonded to one Li and three H atoms to form distorted corner-sharing NLiH3 tetrahedra. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the third N site, N is bonded to one Li and three H atoms to form distorted corner-sharing NLiH3 tetrahedra. All N–H bond lengths are 1.03 Å. In the fourth N site, N is bonded to one Li and three H atoms to form distorted corner-sharing NLiH3 tetrahedra. All N–H bond lengths are 1.03 Å. There are twelve inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one N atom. In the second H site, H is bonded in a single-bond geometry to one N atom. In the third H site, H is bonded in a single-bond geometry to one N atom. In the fourth H site, H is bonded in a single-bond geometry to one N atom. In the fifth H site, H is bonded in a single-bond geometry to one N atom. In the sixth H site, H is bonded in a single-bond geometry to one N atom. In the seventh H site, H is bonded in a single-bond geometry to one N atom. In the eighth H site, H is bonded in a single-bond geometry to one N atom. In the ninth H site, H is bonded in a single-bond geometry to one N atom. In the tenth H site, H is bonded in a single-bond geometry to one N atom. In the eleventh H site, H is bonded in a single-bond geometry to one N atom. In the twelfth H site, H is bonded in a single-bond geometry to one N atom. In four of the Li(NH3)4 clusters, Li is bonded in a tetrahedral geometry to four N atoms. There are a spread of Li–N bond distances ranging from 2.05–2.07 Å. There are four inequivalent N sites. In the first N site, N is bonded to one Li and three H atoms to form distorted corner-sharing NLiH3 tetrahedra. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. In the second N site, N is bonded to one Li and three H atoms to form distorted corner-sharing NLiH3 tetrahedra. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the third N site, N is bonded to one Li and three H atoms to form distorted corner-sharing NLiH3 tetrahedra. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the fourth N site, N is bonded to one Li and three H atoms to form distorted corner-sharing NLiH3 tetrahedra. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. There are twelve inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one N atom. In the second H site, H is bonded in a single-bond geometry to one N atom. In the third H site, H is bonded in a single-bond geometry to one N atom. In the fourth H site, H is bonded in a single-bond geometry to one N atom. In the fifth H site, H is bonded in a single-bond geometry to one N atom. In the sixth H site, H is bonded in a single-bond geometry to one N atom. In the seventh H site, H is bonded in a single-bond geometry to one N atom. In the eighth H site, H is bonded in a single-bond geometry to one N atom. In the ninth H site, H is bonded in a single-bond geometry to one N atom. In the tenth H site, H is bonded in a single-bond geometry to one N atom. In the eleventh H site, H is bonded in a single-bond geometry to one N atom. In the twelfth H site, H is bonded in a single-bond geometry to one N atom. In each P cluster, there are eleven inequivalent P sites. In the first P site, P is bonded in a trigonal non-coplanar geometry to three P atoms. There are a spread of P–P bond distances ranging from 2.17–2.27 Å. In the second P site, P is bonded in a trigonal non-coplanar geometry to three P atoms. There are a spread of P–P bond distances ranging from 2.17–2.26 Å. In the third P site, P is bonded in a trigonal non-coplanar geometry to three P atoms. There are a spread of P–P bond distances ranging from 2.18–2.27 Å. In the fourth P site, P is bonded in a trigonal non-coplanar geometry to three P atoms. There are one shorter (2.17 Å) and one longer (2.28 Å) P–P bond lengths. In the fifth P site, P is bonded in a trigonal non-coplanar geometry to three P atoms. There are one shorter (2.18 Å) and one longer (2.26 Å) P–P bond lengths. In the sixth P site, P is bonded in a trigonal non-coplanar geometry to three P atoms. There are one shorter (2.18 Å) and one longer (2.27 Å) P–P bond lengths. In the seventh P site, P is bonded in a trigonal non-coplanar geometry to three P atoms. In the eighth P site, P is bonded in an L-shaped geometry to two P atoms. In the ninth P site, P is bonded in an L-shaped geometry to two P atoms. In the tenth P site, P is bonded in a trigonal non-coplanar geometry to three P atoms. In the eleventh P site, P is bonded in an L-shaped geometry to two P atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Agricultural Impacts on Nitrogen Cycling: Climate and Air Pollution (Final Technical Report)

We have successfully added a parameterization of ammonia emissions from synthetic fertilizer and manure from agriculture to Earth System Models. We have evaluated how emissions change in the future and the processes driving these changes. We have examined the impact of agricultural ammonia emissions on present-day air quality and have evaluated the impact of resolving the emissions with high temporal resolution. We have also examined the impact of how Earth System Models treat the cycling of emissions in soils. Our code, the Flows of Agricultural Nitrogen – version 2 – model (FANv2) has been run in both the CLM framework and the ELM framework. To my knowledge the code has not yet been fully implemented into ELM. Volatilization of ammonia (NH3) from fertilizers and livestock wastes forms a significant pathway of nitrogen losses in agricultural ecosystems and constitutes the largest source of atmospheric emissions of NH3. We have provided a major update to the process model FAN (Flow of Agricultural Nitrogen), which evaluates NH3 emissions interactively within an Earth system model; in this work, the Community Earth System Model (CESM) is used. The updated version (FANv2) includes a more detailed treatment of both physical and agricultural processes, which allows the model to differentiate between the volatilization losses from animal housings, manure storage, grazed pastures, and the application of manure and different types of mineral fertilizers. The modeled ammonia emissions are first evaluated at a local scale against experimental data for various types of fertilizers and manure, and they are subsequently run globally to evaluate NH3 emissions for 2010–2015 based on gridded datasets of fertilizer use and livestock populations. Comparison of regional emissions shows that FANv2 agrees with previous inventories for North America and Europe and is within the range of previous inventories for China. However, due to higher NH3 emissions in Africa, India, and Latin America, the global emissions simulated by FANv2(48 Tg N) are 30 %–40 % higher than in the existing inventories.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Mitigation of Gaseous Emissions from Stored Swine Manure with Biochar: Effect of Dose and Reapplication on a Pilot-Scale

Rural communities are affected by gaseous emissions from intensive livestock production. Practical mitigation technologies are needed to minimize emissions from stored manure and improve air quality inside barns. In our previous research, the one-time surficial application of biochar to swine manure significantly reduced emissions of NH3 and phenol. We observed that the mitigation effect decreased with time during the 30-day trials. In this research, we hypothesized that bi-weekly reapplication of biochar could improve the mitigation effect on a wider range of odorous compounds using a larger scale and longer trials. The objective was to evaluate the effectiveness of biochar dose and reapplication on mitigation of targeted gases (NH3, odorous, volatile organic compounds VOCs, odor, greenhouse gases (GHG)) from stored swine manure on a pilot-scale setup over 8-weeks. The bi-weekly reapplication of the lower biochar dose (2 kg/m2) showed much higher significant percentage reductions in emissions for NH3 (33% without and 53% with reapplication) and skatole (42% without and 80% with reapplication), respectively. In addition, the reapplication resulted in the emergence of a statistical significance to the mitigation effect for all other targeted VOCs. Specifically, for indole, the percentage reduction improved from 38% (p = 0.47, without reapplication) to 78% (p = 0.018, with reapplication). For phenol, the percentage reduction improved from 28% (p = 0.71, without reapplication) to 89% (p = 0.005, with reapplication). For p-cresol, the percentage reduction improved from 31% (p = 0.86, without reapplication) to 74% (p = 0.028, with reapplication). For 4-ethyl phenol, the percentage emissions reduction improved from 66% (p = 0.44, without reapplication) to 87% (p = 0.007, with reapplication). The one-time 2 kg/m2 and 4 kg/m2 treatments showed similar effectiveness in mitigating all targeted gases, and no statistical difference was found between the dosages. The one-time treatments showed significant percentage reductions of 33% and 42% and 25% and 48% for NH3 and skatole, respectively. The practical significance is that the higher (one-time) biochar dose may not necessarily result in improved performance over the 8-week manure storage, but the bi-weekly reapplication showed significant improvement in mitigating NH3 and odorous VOCs. The lower dosages and the frequency of reapplication on the larger-scale should be explored to optimize biochar treatment and bring it closer to on-farm trials.

Chen, Baitong (ORCID:0000000266071253)↗
DOE OSTI2021

Fine Aerosol Acidity and Water during Summer in the Eastern North Atlantic

Aerosol pH governs many important atmospheric processes that occur in the marine boundary layer, including regulating halogen and sulfur chemistries, and nutrient fertilization of surface ocean waters. In this study, we investigated the acidity of PM1 over the eastern North Atlantic during the Aerosol and Cloud Experiments in Eastern North Atlantic (ACE-ENA) aircraft campaign. The ISORROPIA-II thermodynamic model was used to predict PM1 pH and water. We first investigated the sensitivities of PM1 pH and water predictions to gas-phase NH3 and HNO3 concentrations. Our sensitivity analysis indicated that even though NH3 and HNO3 were present at very low concentrations in the eastern North Atlantic during the campaign, PM1 pH calculations can still be sensitive to NH3 concentrations. Specifically, NH3 was needed to constrain the pH of populations of PM1 that had low mass concentrations of NH4+ and non-volatile cations (NVCs). We next assumed that gas-phase NH3 and HNO3 concentrations during the campaign were 0.15 and 0.09 µg m−3, respectively, based on previous measurements conducted in the eastern North Atlantic. Using the assumption that PM1 were internally mixed (i.e., bulk PM1), we determined that PM1 pH ranged from 0.3–8.6, with a mean pH of 5.0 ± 2.3. The pH depended on both Hair+ and Wi. Hair+ was controlled primarily by the NVCs/SO42− molar ratio, while Wi was controlled by the SO42− mass concentration and RH. Changes in pH with altitude were driven primarily by changes in SO42−. Since aerosols in marine atmospheres are rarely internally mixed, the scenario where non-sea salt species and sea-salt species were present in two separate aerosol modes in the PM1 (i.e., completely externally mixed) was also considered. Smaller pH values were predicted for the aerosol mode comprised only of non-sea salt species compared to the bulk PM1 (difference of around 1 unit on average). This was due to the exclusion of sea-salt species (especially hygroscopic alkaline NVCs) in this aerosol mode, which led to increases in Hair+ values and decreases in Wi values. This result demonstrated that assumptions of aerosol mixing states can impact aerosol pH predictions substantially, which will have important implications for evaluating the nature and magnitude of pH-dependent atmospheric processes that occur in the marine boundary layer.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

All-aerosol-jet-printed highly sensitive and selective polyaniline-based ammonia sensors: a route toward low-cost, low-power gas detection

In this work, we report the design and scalable fabrication of a low-cost and low-power polyaniline-based (PANI) ammonia (NH3) gas sensor on polyimide (PI) substrates using additive manufacturing techniques. The silver interdigitated electrode (IDE) arrays and conducting polymer films are printed onto PI using a direct-write technology of aerosol-jet printing. Morphological characteristics are examined by scanning electron microscopy and energy-dispersive X-ray analysis which reveal homogeneously printed PANI film on the IDE platform. The gas sensing performance is evaluated in the analytical early leak detection range of 5–1000 ppm NH3 in air as a function of both thermal (23 °C, 50 °C, 80 °C) and relative humidity (RH = 0%, 30%, 50%) exposures. The sensor exhibits sensitivity down to 5 ppm NH3 with a sub-ppm detection limit and good repeatability. We observe rapid NH3 detection at 0% RH with very extended times for equilibration and recovery. However, at both 30 and 50% RH, the room temperature response and recovery times are reduced to only about 1 min and 5 min, respectively. Experiments also reveal good sensitivity toward the analyte even at higher operating temperatures. Present results merit the practical application of aerosol-jet-printed, low-power sensors for industrial applications where low-level hazardous gas detection is essential.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Laser-induced electron diffraction of the ultrafast umbrella motion in ammonia

Visualizing molecular transformations in real-time requires a structural retrieval method with Ångström spatial and femtosecond temporal atomic resolution. Imaging of hydrogen-containing molecules additionally requires an imaging method sensitive to the atomic positions of hydrogen nuclei, with most methods possessing relatively low sensitivity to hydrogen scattering. Laser-induced electron diffraction (LIED) is a table-top technique that can image ultrafast structural changes of gas-phase polyatomic molecules with sub-Ångström and femtosecond spatiotemporal resolution together with relatively high sensitivity to hydrogen scattering. Here, we image the umbrella motion of an isolated ammonia molecule (NH3) following its strong-field ionization. Upon ionization of a neutral ammonia molecule, the ammonia cation (NH3+) undergoes an ultrafast geometrical transformation from a pyramidal (ΦHNH=107°) to planar (ΦHNH=120°) structure in approximately 8 femtoseconds. Using LIED, we retrieve a near-planar (ΦHNH=117 ± 5°) field-dressed NH3+ molecular structure 7.8−9.8 femtoseconds after ionization. Our measured field-dressed NH3+ structure is in excellent agreement with our calculated equilibrium field-dressed structure using quantum chemical ab initio calculations.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

A survey of deuterated ammonia in the Cepheus star-forming region L1251

ABSTRACT Understanding the chemical processes during starless core and prestellar core evolution is an important step in understanding the initial stages of star and disc formation. This project is a study of deuterated ammonia, o-NH2D, in the L1251 star-forming region towards Cepheus. Twenty-two dense cores (20 of which are starless or prestellar, and two of which have a protostar), previously identified by p-NH3 (1,1) observations, were targeted with the 12m Arizona Radio Observatory telescope on Kitt Peak. o-NH2D J$_{\rm {K_a} \rm {K_c}}^{\pm } =$$1_{11}^{+} \rightarrow 1_{01}^{-}$ was detected in 13 (59 per cent) of the NH3-detected cores with a median sensitivity of $\sigma _{T_{mb}} = 17$ mK. All cores detected in o-NH2D at this sensitivity have p-NH3 column densities >1014 cm−2. The o-NH2D column densities were calculated using the constant excitation temperature (CTEX) approximation while correcting for the filling fraction of the NH3 source size. The median deuterium fraction was found to be 0.11 (including 3σ upper limits). However, there are no strong, discernible trends in plots of deuterium fraction with any physical or evolutionary variables. If the cores in L1251 have similar initial chemical conditions, then this result is evidence of the cores physically evolving at different rates.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Materials Data on Ag2H21N7(ClO4)2 by Materials Project

(Ag(NH3)2)2(AgN3H7O4)2(NH3)2(H2)2(NH2O)2H2O2(ClO2)2Cl2 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one ammonia molecule, one hydrochloric acid molecule, one hydrogen molecule, one hydroxylamine molecule, one hypochlorous acid;hydrate molecule, one water molecule, one Ag(NH3)2 cluster, and one AgN3H7O4 cluster. In the Ag(NH3)2 cluster, Ag1+ is bonded in a distorted bent 120 degrees geometry to two N+0.71- atoms. There are one shorter (2.14 Å) and one longer (2.15 Å) Ag–N bond lengths. There are two inequivalent N+0.71- sites. In the first N+0.71- site, N+0.71- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+ and three H1+ atoms. All N–H bond lengths are 1.02 Å. In the second N+0.71- site, N+0.71- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+ and three H1+ atoms. There is two shorter (1.02 Å) and one longer (1.06 Å) N–H bond length. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the AgN3H7O4 cluster, Ag1+ is bonded in a 2-coordinate geometry to three N+0.71- atoms. There are a spread of Ag–N bond distances ranging from 2.05–2.71 Å. There are three inequivalent N+0.71- sites. In the first N+0.71- site, N+0.71- is bonded in a 2-coordinate geometry to one Ag1+, two H1+, and one O2- atom. Both N–H bond lengths are 1.03 Å. The N–O bond length is 1.46 Å. In the second N+0.71- site, N+0.71- is bonded in a distorted bent 120 degrees geometry to one Ag1+ and one H1+ atom. The N–H bond length is 1.04 Å. In the third N+0.71- site, N+0.71- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+ and three H1+ atoms. All N–H bond lengths are 1.03 Å. There are seven inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one N+0.71- atom. In the seventh H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.06 Å) and one longer (1.48 Å) H–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one N+0.71- and one O2- atom. The O–O bond length is 1.34 Å. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one H1+ and one O2- atom. In the third O2- site, O2- is bonded in a single-bond geometry to one H1+ and one O2- atom. The O–O bond length is 1.34 Å. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one O2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NiH36(C5N)12 by Materials Project

Ni(NH3)6(C)60(NH3)6 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of six ammonia molecules, one fullerene molecule, and one Ni(NH3)6 cluster. In the Ni(NH3)6 cluster, Ni is bonded in an octahedral geometry to six N atoms. There are a spread of Ni–N bond distances ranging from 2.15–2.19 Å. There are three inequivalent N sites. In the first N site, N is bonded in a distorted trigonal non-coplanar geometry to one Ni and three H atoms. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the second N site, N is bonded in a distorted trigonal non-coplanar geometry to one Ni and three H atoms. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the third N site, N is bonded in a distorted trigonal non-coplanar geometry to one Ni and three H atoms. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. There are nine inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one N atom. In the second H site, H is bonded in a single-bond geometry to one N atom. In the third H site, H is bonded in a single-bond geometry to one N atom. In the fourth H site, H is bonded in a single-bond geometry to one N atom. In the fifth H site, H is bonded in a single-bond geometry to one N atom. In the sixth H site, H is bonded in a single-bond geometry to one N atom. In the seventh H site, H is bonded in a single-bond geometry to one N atom. In the eighth H site, H is bonded in a single-bond geometry to one N atom. In the ninth H site, H is bonded in a single-bond geometry to one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li2P7(H3N)9 by Materials Project

(Li(NH3)4)2(P)7NH3 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two ammonia molecules, fourteen phosphine molecules, and four Li(NH3)4 clusters. In two of the Li(NH3)4 clusters, Li1+ is bonded in a tetrahedral geometry to four N3- atoms. There are a spread of Li–N bond distances ranging from 2.07–2.09 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded to one Li1+ and three H+0.78+ atoms to form distorted corner-sharing NLiH3 tetrahedra. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. In the second N3- site, N3- is bonded to one Li1+ and three H+0.78+ atoms to form distorted corner-sharing NLiH3 tetrahedra. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. In the third N3- site, N3- is bonded to one Li1+ and three H+0.78+ atoms to form distorted corner-sharing NLiH3 tetrahedra. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the fourth N3- site, N3- is bonded to one Li1+ and three H+0.78+ atoms to form distorted corner-sharing NLiH3 tetrahedra. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. There are twelve inequivalent H+0.78+ sites. In the first H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the second H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the third H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the fourth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the fifth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the sixth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the seventh H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the eighth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the ninth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the tenth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the eleventh H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the twelfth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In two of the Li(NH3)4 clusters, Li1+ is bonded in a tetrahedral geometry to four N3- atoms. There are two shorter (2.06 Å) and two longer (2.08 Å) Li–N bond lengths. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded to one Li1+ and three H+0.78+ atoms to form distorted corner-sharing NLiH3 tetrahedra. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. In the second N3- site, N3- is bonded to one Li1+ and three H+0.78+ atoms to form distorted corner-sharing NLiH3 tetrahedra. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the third N3- site, N3- is bonded to one Li1+ and three H+0.78+ atoms to form distorted corner-sharing NLiH3 tetrahedra. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the fourth N3- site, N3- is bonded to one Li1+ and three H+0.78+ atoms to form distorted corner-sharing NLiH3 tetrahedra. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. There are twelve inequivalent H+0.78+ sites. In the first H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the second H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the third H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the fourth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the fifth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the sixth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the seventh H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the eighth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the ninth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the tenth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the eleventh H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom. In the twelfth H+0.78+ site, H+0.78+ is bonded in a single-bond geometry to one N3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MnH36(C5N)12 by Materials Project

Mn(NH3)6(C)60(NH3)6 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of six ammonia molecules, one fullerene molecule, and one Mn(NH3)6 cluster. In the Mn(NH3)6 cluster, Mn is bonded in an octahedral geometry to six N atoms. There are a spread of Mn–N bond distances ranging from 2.33–2.40 Å. There are three inequivalent N sites. In the first N site, N is bonded in a distorted trigonal non-coplanar geometry to one Mn and three H atoms. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. In the second N site, N is bonded in a distorted trigonal non-coplanar geometry to one Mn and three H atoms. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. In the third N site, N is bonded in a distorted trigonal non-coplanar geometry to one Mn and three H atoms. There is two shorter (1.03 Å) and one longer (1.04 Å) N–H bond length. There are nine inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one N atom. In the second H site, H is bonded in a single-bond geometry to one N atom. In the third H site, H is bonded in a single-bond geometry to one N atom. In the fourth H site, H is bonded in a single-bond geometry to one N atom. In the fifth H site, H is bonded in a single-bond geometry to one N atom. In the sixth H site, H is bonded in a single-bond geometry to one N atom. In the seventh H site, H is bonded in a single-bond geometry to one N atom. In the eighth H site, H is bonded in a single-bond geometry to one N atom. In the ninth H site, H is bonded in a single-bond geometry to one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TiH42N14Cl3 by Materials Project

(Ti(NH3)8)2(NH3)12(Cl2)3 is Ammonia-derived structured and crystallizes in the monoclinic P2/c space group. The structure is zero-dimensional and consists of twelve ammonia molecules, six hydrochloric acid molecules, and two Ti(NH3)8 clusters. In each Ti(NH3)8 cluster, Ti3+ is bonded in a 8-coordinate geometry to eight N3- atoms. There are two shorter (2.29 Å) and six longer (2.30 Å) Ti–N bond lengths. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal non-coplanar geometry to one Ti3+ and three H1+ atoms. There are a spread of N–H bond distances ranging from 1.02–1.04 Å. In the second N3- site, N3- is bonded in a trigonal non-coplanar geometry to one Ti3+ and three H1+ atoms. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the third N3- site, N3- is bonded in a trigonal non-coplanar geometry to one Ti3+ and three H1+ atoms. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. In the fourth N3- site, N3- is bonded in a trigonal non-coplanar geometry to one Ti3+ and three H1+ atoms. All N–H bond lengths are 1.03 Å. There are twelve 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. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Innovative SCR Materials and System for Low Temperature - CRADA 350 (Abstract)

The aim of this CRADA is focused on providing a new enabling SCR catalyst system that will function at very high efficiency to attain the most demanding emissions regulations and thereby facilitate the market introduction of advanced powertrains that will support domestic energy independence and security. Future powertrains, that will be significantly more efficient than currently available technologies, will be needed by automotive manufacturers to meet rapidly increasing CAFE and GHG standards. However, these powertrains cannot enter into the US light duty vehicle market unless they are coupled with an aftertreatment system that will sufficiently remediate tailpipe emissions to meet EPA Tier III and California SULEV emissions standards. The low temperature exhaust associated with these powertrains is especially challenging for any current aftertreatment technology to meet these standards. The key focus of this CRADA is to further develop newly invented materials for the selective catalytic reduction (SCR) of NOx by ammonia (NH3) that show promise for significantly reducing ‘light-off’ temperatures compared to current commercial catalysts. Specifically, the goal of the proposed work is to achieve ‘light-off’ of NH3 SCR at 150 ºC in order to realize conversion efficiencies of 90% at these low temperatures. This will enable deployment of lean combustion powertrains with significantly increased fuel efficiencies but lower exhaust temperatures. To accomplish this overall goal, it will be essential to also identify an appropriate NH3 supply strategy for the SCR aftertreatment device that can controllably deliver NH3 at these low temperatures.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Experimental Investigation of Air-Fuel Equivalence Ratio Effects on Advanced Dual-fuel Diesel/Ammonia Combustion on a Single-Cylinder Medium-Duty Diesel Engine at High Load

Ammonia (NH3) has gathered a lot of interest as a low-lifecycle-carbon fuel in sectors with high weight and distance requirements, such as shipping. The International Maritime Organization (IMO) mandates a 70-80% greenhouse gas (GHG) reduction by 2040, which is only possible with advanced engine technologies and fuels like NH3. Prior research studies at the US Department of Energy’s Oak Ridge National Laboratory have shown strong performance with NH3 under dual-fuel mode using conventional diesel combustion (CDC) manifold air pressure (MAP) settings. Diesel airflow was initially used to simplify retrofitting (no turbocharger modification), which resulted in air-fuel equivalence ratios (λ) greater than 1.5. To characterize potential improvements in dual-fuel NH3 combustion performance at richer in-cylinder conditions, a global λ sweep using a diesel pilot ignition (DPI) strategy with diesel fuel injected near top-dead center (TDC) and a reactivity-controlled compression ignition (RCCI) injection strategy with diesel fuel injected earlier during the compression stroke were compared. The experiments were conducted at 1200 RPM and 12.6 bar (75% load), and λ was varied by decreasing the commanded air flow to the engine at greater than 90% ammonia energy substitution (AES) level. A diesel injection timing sweep was conducted for both the combustion modes at fixed λ, and the timing with the lowest engine-out N2O emissions was identified. The results indicated an optimal balance between CO2, eq and thermal efficiency benefits for both DPI and RCCI injection strategy cases compared to CDC at a λ of 1.4. The indicated N-based emissions exhibited a strong correlation to the ratio of CA5–50 and ignition delay for DPI, but no apparent trend emerged for the RCCI injection strategy at the tested boundary conditions.

Tyrewala, Daanish [ORNL] (ORCID:0000000208599324)↗
DOE OSTI2025

Gaseous Ammonia Measurements at the S2 site for the CoURAGE campaign

This dataset contains measurements of gaseous ammonia (NH3(g)) at the S2 (Mt. Airy) site during the CoURAGE study from April to June 2025. This dataset includes 10-minute and 30-minute average NH3(g) concentrations in units of micrograms per cubic meter. Measurements are conducted with an AiRRmonia NH3 analyzer manufactured by RR Mechatronics. A data flag of -999 indicates missing data due to the instrument being offline (maintenance, calibration, etc.) while a data flag of -888 indicates measurements below the instrument LOD (LOD = 0.1 micrograms per cubic meter). The uncertainty of the measurements is 15%.

AiRRmonia NH3 analyzer↗
DOE OSTI2025

Study on ammonia and dimethyl ether oxidation and kinetic interaction up to 100 atm

NH 3 and DME dual fuel oxidation and kinetic coupling are experimentally studied by using a supercritical pressure jet-stirred reactor (SP-JSR) at 20 and 100 atm, over a temperature range of 500–900 K, and at fuel-lean and stoichiometric conditions with NH 3 to DME molar ratios of 4 and 0.62, respectively. An HP-Mech model for high-pressure NH3/DME oxidation is developed based on our previous studies and it shows generally better performance than other models in the literature on high-pressure oxidation experiments. Due to DME’s strong low-temperature reactivity, it dramatically enhances the oxidation of NH3 at low temperature. However, the effect of NH 3 on DME oxidation varies with temperature. At low temperatures, NH 3 inhibits low-temperature reactivity by consuming OH radicals. In addition, the NH 2 and NO x formation from NH 3 further suppresses the low-temperature DME reactivity by reducing alkylperoxyl and O 2 QOOH radicals via RO 2 + NH 2 = RO + H 2 NO, RO 2 + NO = RO + NO 2 and O 2 QOOH + NO = 2CH 2 O + HO 2 + NO 2 . At intermediate temperatures, due to enhanced kinetic coupling of NH 2 /NO x /HO 2 chemistry, DME oxidation is significantly promoted. It is found that there are two major NH 2 /NO x /HO 2 coupling pathways for OH radical production brought by NH 3 : (1) NH 2 + HO 2 = H 2 NO + OH and (2) NH 2 + NO 2 = H 2 NO + NO with NO + HO 2 = OH + NO 2 . Moreover, the resulting H 2 NO will further contribute to OH production via the H 2 NO/NO x /HONO coupling pathways: H 2 NO + NO 2 = HNO + HONO, HNO + NO 2 = HONO + NO, and HONO (+M) = OH + NO (+M). These new NH 2 /NO x /HO 2 and H 2 NO/NO x /HONO pathways play a critical role in promoting DME oxidation at intermediate temperatures. Novelty and Significance Statement: Blending NH 3 with DME can significantly enhance the reactivity of NH 3 and facilitate its practical application in advanced internal combustion engines. NH 3 /DME oxidation is studied in a novel supercritical pressure jet-stirred reactor up to 100 atm, a much higher pressure than previous studies. An interesting non-monotonic effect of NH3 addition on fuel oxidation has been found. Unique kinetic couplings of NH2/HO2/NOx and H2NO/NOx/HONO brough by NH3 and DME blending are identified to play important roles in radical generation and reactivity promotion. The valuable experimental data and key kinetics revealed in the current work can tremendously improve our understanding of NH 3 /DME oxidation via NO x /RO 2 and NH 2 / H 2 NO/HO 2 /NO x kinetic couplings at low to intermediate temperatures.

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

Temperature-dependent solid electrolyte interphase reactions drive performance in lithium-mediated nitrogen reduction to ammonia

The solid electrolyte interphase (SEI) is a vital component to control mass transport and selectivity in the lithium-mediated reduction of N 2 to NH 3 (Li-N 2 R). Finding strategies that generate the optimal SEI, a complex network of organic and inorganic species, can potentially improve Li-N 2 R performance. Here, we unravel structure-property relationships of the SEI by correlating its composition with the NH 3 faradaic efficiency (FENH3). By modifying the reaction temperature, we alter electrolyte decomposition reactions and observe changes in the SEI that explain FE NH3 trends between electrolyte solvents. We quantify a complex reaction environment at elevated temperatures where SEI formation is counteracted by etching reactions. This tradeoff leads to temporal fluctuations of FE NH3 , but the maximal FE NH3 can reach up to 40%, the highest value reported for batch cells at ambient pressure, thus far. In conclusion, our work underscores the potential of novel electrolytes that steer SEI selectivity and, ultimately, improve Li-N 2 R performance.

electrocatalytic nitrogen reduction↗
DOE OSTI2021

Ship-in-a-Bottle Synthesis of High Concentration of N2 Molecules in a Cage-Structured Electride

We report the formation of neutral nitrogen molecules in the cages of [Ca12Al14O32]2+ (C12A7) framework compensated by extra-framework anions. NH3 treatment of C12A7 electride (C12A7:e–) at 800 °C leads to the formation of N2 and NH2– species in the C12A7 cages. N2 and NHx species in the cages are identified using the Raman spectroscopy of 14NH3 and 15NH3-treated C12A7:e–. The concentration of H and N in the C12A7 cages after NH3 treatment is ~1021 cm–3. We propose a two-step mechanism, supported by density functional theory (DFT) modeling, of N2 incorporation into the C12A7 cages: incorporation of NH2– formed from decomposition of NH3 at C12A7:e– surface followed by the NH2- species reacting to form N2 molecules. Encapsulation of neutral molecules, as opposed to negatively charged species reported in C12A7 previously, offers new opportunities for trapping and storing gaseous substances in nano-porous materials.

Nakao, Takuya↗