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At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on NaV5H18N2O19 by Materials Project

Na(H2O)5V5O14(NH4)2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four ammonium molecules, one Na(H2O)5 cluster, and one V5O14 cluster. In the Na(H2O)5 cluster, Na1+ is bonded to six O2- atoms to form edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.37–2.49 Å. There are ten inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Na1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the V5O14 cluster, there are five inequivalent V5+ sites. In the first V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.62–2.44 Å. In the second V5+ site, V5+ is bonded to six O2- atoms to form distorted edge-sharing VO6 octahedra. There are a spread of V–O bond distances ranging from 1.73–2.09 Å. In the third V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.66–2.27 Å. In the fourth V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.65–2.30 Å. In the fifth V5+ site, V5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.64–2.36 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to two V5+ atoms. In the second O2- site, O2- is bonded in a trigonal non-coplanar geometry to three V5+ atoms. In the third O2- site, O2- is bonded in a trigonal non-coplanar geometry to three V5+ atoms. In the fourth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the sixth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the eighth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two V5+ atoms. In the tenth O2- site, O2- is bonded to six V5+ atoms to form distorted edge-sharing OV6 octahedra. In the eleventh O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the twelfth O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms. In the thirteenth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the fourteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two V5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaHgH16(BrO2)4 by Materials Project

Ca(H2O)8HgBr4 is Vulcanite-like structured and crystallizes in the orthorhombic Cmce space group. The structure is zero-dimensional and consists of eight Ca(H2O)8 clusters and eight HgBr4 clusters. In each Ca(H2O)8 cluster, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.46–2.60 Å. There are eight inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one Ca2+ and two H1+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to one Ca2+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Ca2+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a water-like geometry to one Ca2+ and two H1+ atoms. In each HgBr4 cluster, Hg2+ is bonded in a tetrahedral geometry to four Br1- atoms. There are a spread of Hg–Br bond distances ranging from 2.64–2.70 Å. There are three inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a single-bond geometry to one Hg2+ atom. In the second Br1- site, Br1- is bonded in a single-bond geometry to one Hg2+ atom. In the third Br1- site, Br1- is bonded in a single-bond geometry to one Hg2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PrH18(BrO6)3 by Materials Project

Pr(H2O)9(BrO3)3 crystallizes in the hexagonal P6_3mc space group. The structure is zero-dimensional and consists of six hypobromous acid;dihydrate molecules and two Pr(H2O)9 clusters. In each Pr(H2O)9 cluster, Pr3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Pr–O bond distances ranging from 2.51–2.55 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one Pr3+ and two equivalent H1+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to one Pr3+ and two equivalent H1+ atoms. In the third O2- site, O2- is bonded in a water-like geometry to one Pr3+ and two equivalent H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li3H24Ru(ClO2)6 by Materials Project

(Li(H2O)4)3RuCl6 is Tungsten Carbide-like structured and crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of four ruthenium(6+) hexachloride molecules and four Li(H2O)4 clusters. In each Li(H2O)4 cluster, there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six O2- atoms to form face-sharing LiO6 octahedra. There are a spread of Li–O bond distances ranging from 2.16–2.19 Å. In the second Li1+ site, Li1+ is bonded to six O2- atoms to form face-sharing LiO6 octahedra. There are two shorter (2.14 Å) and four longer (2.16 Å) Li–O bond lengths. There are twelve inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one Li1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to one Li1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Li1+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to two Li1+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to two Li1+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to two Li1+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BiH18C3S3(O2F)9 by Materials Project

Bi(H2O)9(CF3)3(SO3)3 crystallizes in the hexagonal P6_3/m space group. The structure is zero-dimensional and consists of six fluoroform molecules, six sulfur trioxide molecules, and two Bi(H2O)9 clusters. In each Bi(H2O)9 cluster, Bi5+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are six shorter (2.49 Å) and three longer (2.61 Å) Bi–O bond lengths. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one Bi5+ and two H1+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to one Bi5+ and two equivalent H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2V9MoH35(N2O19)2 by Materials Project

(Na(H2O)5)2V9MoO28(NH4)3NH3 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one ammonia molecule, three ammonium molecules, one Na(H2O)5 cluster, and one V9MoO28 cluster. In the Na(H2O)5 cluster, there are two inequivalent Na sites. In the first Na site, Na is bonded to six O atoms to form edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.36–2.53 Å. In the second Na site, Na is bonded to six O atoms to form edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.40–2.48 Å. There are twenty inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the second H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the third H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the fourth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the fifth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the sixth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the seventh H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the eighth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the ninth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the tenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the eleventh H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the twelfth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the thirteenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the fourteenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the fifteenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the sixteenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the seventeenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the eighteenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.99 Å. In the nineteenth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the twentieth H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. There are ten inequivalent O sites. In the first O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the second O site, O is bonded in a distorted water-like geometry to two Na and two H atoms. In the third O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the fourth O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the fifth O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the sixth O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the seventh O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the eighth O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the ninth O site, O is bonded in a distorted water-like geometry to two Na and two H atoms. In the tenth O site, O is bonded in a distorted water-like geometry to one Na and two H atoms. In the V9MoO28 cluster, there are nine inequivalent V sites. In the first V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.63–2.32 Å. In the second V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.67–2.25 Å. In the third V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.62–2.42 Å. In the fourth V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.64–2.38 Å. In the fifth V site, V is bonded to six O atoms to form distorted edge-sharing VO6 octahedra. There are a spread of V–O bond distances ranging from 1.73–2.12 Å. In the sixth V site, V is bonded to six O atoms to form distorted edge-sharing VO6 octahedra. There are a spread of V–O bond distances ranging from 1.73–2.12 Å. In the seventh V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.65–2.34 Å. In the eighth V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.61–2.47 Å. In the ninth V site, V is bonded in a 6-coordinate geometry to six O atoms. There are a spread of V–O bond distances ranging from 1.66–2.31 Å. Mo is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Mo–O bond distances ranging from 1.74–2.33 Å. There are twenty-eight inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the second O site, O is bonded in a single-bond geometry to one V atom. In the third O site, O is bonded to six V atoms to form distorted edge-sharing OV6 octahedra. In the fourth O site, O is bonded in a single-bond geometry to one V atom. In the fifth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the sixth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the seventh O site, O is bonded in a trigonal non-coplanar geometry to two V and one Mo atom. In the eighth O site, O is bonded in a trigonal non-coplanar geometry to three V atoms. In the ninth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the tenth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the eleventh O site, O is bonded in a single-bond geometry to one V atom. In the twelfth O site, O is bonded in a water-like geometry to two V atoms. In the thirteenth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the fourteenth O site, O is bonded in a single-bond geometry to one V atom. In the fifteenth O site, O is bonded in a single-bond geometry to one V atom. In the sixteenth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the seventeenth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the eighteenth O site, O is bonded in a single-bond geometry to one V atom. In the nineteenth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the twentieth O site, O is bonded in a bent 120 degrees geometry to one V and one Mo atom. In the twenty-first O site, O is bonded in a trigonal non-coplanar geometry to two V and one Mo atom. In the twenty-second O site, O is bonded in a trigonal non-coplanar geometry to three V atoms. In the twenty-third O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the twenty-fourth O site, O is bonded in a bent 120 degrees geometry to two V atoms. In the twenty-fifth O site, O is bonded in a single-bond geometry to one Mo atom. In the twenty-sixth O site, O is bonded to five V and one Mo atom to form edge-sharing OV5Mo octahedra. In the twenty-seventh O site, O is bonded in a single-bond geometry to one V atom. In the twenty-eighth O site, O is bonded in a bent 120 degrees geometry to one V and one Mo atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Oxygen diffusion in garnet: Experimental calibration and implications for timescales of metamorphic processes and retention of primary O isotopic signatures

Knowledge of oxygen diffusion in garnet is crucial for a correct interpretation of oxygen isotope signatures in natural samples. A series of experiments was undertaken to determine the diffusivity of oxygen in garnet, which remains poorly constrained. The first suite included high-pressure (HP), nominally dry experiments performed in piston-cylinder apparatus at: (1) T = 1050–1600 °C and P = 1.5 GPa and (2) T = 1500 °C and P = 2.5 GPa using yttrium aluminum garnet (YAG; Y3Al5O12) cubes. Second, HP H2O-saturated experiments were conducted at T = 900 °C and P = 1.0–1.5 GPa, wherein YAG crystals were packed into a YAG + Corundum powder, along with 18O-enriched H2O. Third, 1 atm experiments with YAG cubes were performed in a gas-mixing furnace at T = 1500–1600 °C under Ar flux. Finally, an experiment at T = 900 °C and P = 1.0 GPa was done using a pyrope cube embedded into pyrope powder and 18O-enriched H2O. Experiments using grossular were not successful. Profiles of 18O/(18O+16O) in the experimental charges were analyzed with three different secondary ion mass spectrometers (SIMS): sensitive high-resolution ion microprobe (SHRIMP II and SI), CAMECA IMS-1280, and NanoSIMS. Considering only the measured length of 18O diffusion profiles, similar results were obtained for YAG and pyrope annealed at 900 °C, suggesting limited effects of chemical composition on oxygen diffusivity. However, in both garnet types, several profiles deviate from the error function geometry, suggesting that the behavior of O in garnet cannot be fully described as simple concentration-independent diffusion, certainly in YAG and likely in natural pyrope as well. The experimental results are better described by invoking O diffusion via two distinct pathways with an inter-site reaction allowing O to move between these pathways. Modeling this process yields two diffusion coefficients (D values) for O, one of which is approximately two orders of magnitude higher than the other. Taken together, Arrhenius relationships are:logDm2s-1=-7.2(±1.3)+(-321(±32)kJmol-12.303RT) for the slow pathway, andlogDm2s-1=-5.4(±0.7)+(-321(±20)kJmol-12.303RT) for the fast pathway. We interpret the two pathways as representing diffusion following vacancy and inter-stitial mechanisms, respectively. Regardless, our new data suggest that the slow mechanism is prevalent in garnet with natural compositions, and thus is likely to control the retentivity of oxygen isotopic signatures in natural samples. The diffusivity of oxygen is similar to Fe-Mn diffusivity in garnet at 1000–1100 °C and Ca diffusivity at 850 °C. However, the activation energy for O diffusion is larger, leading to lower diffusivities at P-T conditions characterizing crustal metamorphism. Therefore, original O isotopic signatures can be retained in garnets showing major element zoning partially re-equilibrated by diffusion, with the uncertainty caveat of extrapolating the experimental data to lower temperature conditions.

Geochemistry & Geophysics↗
DOE OSTI2022

Carbon Dioxide Flux Measurement System (CO2FLX) Instrument Handbook

The Southern Great Plains (SGP) carbon dioxide flux (CO2 flux) measurement systems provide half-hour average fluxes of CO2, H2O (latent heat), and sensible heat. The fluxes are obtained by the eddy covariance technique, which computes the flux as the mean product of the vertical wind component with CO2 and H2O densities, or estimated virtual temperature. A three-dimensional sonic anemometer is used to obtain the orthogonal wind components and the virtual (sonic) temperature. An infrared gas analyzer is used to obtain the CO2 and H2O densities. A separate sub-system also collects half-hour average measures of meteorological and soil variables from separate 4-m towers.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Computationally Guided Design of Multiple Impurities Tolerant Electrode (Final Report)

The current project was based on a combined experimental and computational approach, which can help recommend better cathode materials under multiple impurities conditions. The PI will mainly take in charge of experimental and computational thermodynamics of the selected cathode materials for the SOFC applications under multiple impurities. While the co-PI will run the electrochemical tests of the cathodes recommended and eventually the long-term degradation tests. At the end of the project, a multiple tolerant cathode material based on the combined experimental and computational approach will be recommended and the reliability of the commonly used accelerated testing will be evaluated. It will address multiple impurities poisoning effect of SO2, CO2, Cr and H2O on the LSM, LSCF and LNO cathodes by identifying the formation of the detrimental secondary phases by XRD, SEM and TEM techniques. And further recommended cathode material will be subjected to electrochemical testing and the most promising ones will be applied to long-term tests. The hybrid approach the PI proposed will not only be applied to the design of multiple impurities tolerant cathodes but will also be considered in the future oxygen electrode applications in SOECs or reversible SOCs. This hybrid computational and experimental approach includes four sections: 1) Investigation of single impurity poisoning on LSM, LSCF and LNO cathodes in the presence of SO2, CO2, Cr. In this section, LSM, LSCF cathodes from FuelCellMaterials and LNO cathodes from Sol-Gel synthesis will be heat-treated in the above single impurity. And the formation of the secondary phases as well as the corresponding simulations will be cross compared, which shows good agreement between each other. Meanwhile, the accelerated testing approach will be evaluated in these systems compared with the previous published work to understand the reliability of the approach. 2) Investigation of multiple impurities poisoning on LSM, LSCF and LNO cathodes in the presence of Cr+H2O, SO2+Cr and SO2+Cr+H2O conditions. We have also applied these 3 candidate cathodes under these multiple impurities’ conditions and the long-term degradation mechanism of the multiple impurities will be understood with the help of the combined experimental and computational approach. Meanwhile, the synergistic effect of those impurities will be compared with the individual ones in the same cathode system to further reveal the actual operating conditions. 3) Electrochemical testing and polarization of the recommended cathode. We have demonstrated very low polarization resistance in LSCF (core)-LSM (shell) electrodes using MSD process and analyzed impedance spectra using DRT analysis and confirming that the low polarization resistance in LSM infiltrated MSD cells is due to reduction in polarization resistance associated with O2-adsorption process. 4). Long-term degradation testing. We have developed a versatile MSD-based process to deposit various continuous coatings onto porous scaffolds and established baseline for longer term Cr-impurity testing in future projects.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Impact of Hydrogen Combustion on the Oxidation-induced Degradation of Heavy-duty Diesel Engine Piston Materials

High temperature ferritic-martensitic steels are candidate materials for heavy-duty diesel engine pistons. The envisioned transition to hydrogen blended fuels is expected to alter the post-combustion atmosphere in the engines, primarily resulting in a higher water vapor content (> 20 vol%) and potentially higher exhaust gas temperatures. The oxidation resistance of existing and newly developed alloys will be a critical life-limiting mechanism under these conditions. In the present work, the oxidation behavior of candidate piston alloys was evaluated in air+10 vol.% H2O and air+30 vol.% H2O at 700°C. Thermal cyclic (1h cycle) exposures were conducted for two variants of commercial UNSS42200 ferritic-martensitic steel and two developmental alloy steels for up to 300h. The developmental alloys each have similar compositions but with one containing elevated Cu levels of 3 wt.%, A significant reduction in resistance to breakaway oxidation was observed for the commercial alloys in the higher water vapor atmosphere. Microstructural characterization (optical metallography, scanning electron microscopy and electron microprobe analysis) revealed the formation of thick Fe-rich oxides even for the high Cr (~12 wt.%) steels after an initial stage of protective oxidation with MnCr-rich spinels. The impact of the evaporation-induced loss of Cr on the time and temperature dependent compositional changes in the alloys was correlated with experimental findings. For the developmental alloys, Cu additions appear to play a role in significantly reducing oxidation kinetics in air+30 vol.% H2O at 700°C.

Pillai, Rishi [ORNL] (ORCID:0000000243688197)↗
DOE OSTI2025

CO2 Profiling System for CO2 Storage (a1-level)

The Southern Great Plains (SGP) carbon dioxide flux (CO2FLUX) measurement systems provide half-hour average fluxes of CO2, H2O (latent heat), sensible heat, and momentum. The systems use the eddy covariance technique, which computes the fluxes from the vertical wind speed in combination with the concentrations of CO2 and H2O, temperature, and horizontal wind speed, respectively. A 3D sonic anemometer obtains the wind components and the temperature, while an infrared gas analyzer measures CO2 and H2O. A sub-system also measures half-hour averages of radiation, meteorological, and soil measurements.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2026

Expert Elicitation for Tidal Energy Levelized Cost of Energy: Present and Future

In accordance with the Government Performance and Results Act (GPRA), H2O annually assesses marine energy technology development resulting from government-funded research and development programs and strategy. For GPRA reporting, H2O uses the levelized cost of energy (LCOE) - which represents the total system cost per unit of energy produced - to measure the progression of marine energy technology development, assess the impact of their research and development programs, and identify future research priorities. To support H2O's GPRA reporting requirements and inform future strategy, the National Laboratory of the Rockies conducted a tidal energy LCOE expert elicitation study to estimate present and future LCOE[AB2.1]. This report describes the motivation and background for the elicitation study, the methodology used to conduct the study, and the study results. It also provides future recommendations for accelerated tidal energy LCOE reduction based on feedback from study participants.

16 TIDAL AND WAVE POWER↗
DOE OSTI2026

Engineering Thermally Resilient and Kinetically Active Reversible Protonic Ceramic Cells via Interfacial Design

Achieving concurrent fast electrode kinetics and long-term thermo-mechanical durability remains a critical challenge for reversible protonic ceramic electrochemical cells (R-PCECs). Herein, we report an interfacial engineering strategy that integrates a perovs.kite-type PrBaRu0.1Co1.9O5+δ (PBRC) nanoparticle layer onto a PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) substrate (PBRC-PBSCF), together with a modified pellet-assisted sintering approach to fabricate dense BaZr0.4Ce0.4Y0.1Yb0.1O3-δ (BZCYYb4411) electrolytes. The in situ reconstructed heterointerface enhances oxygen reduction/evolution reaction (ORR/OER) kinetics, promotes H2O adsorption/dissociation, and improves steam tolerance, as verified by electrochemical measurements and interfacial microstructural analyses. Density functional theory reveals that Ru-induced electronic modulation at the PBRC-PBSCF interface lowers the energy of oxygen vacancy formation and optimizes the position of the O 2p band center, thereby accelerating oxygen redox kinetics and stabilizing the interface. The resulting R-PCECs deliver an excellent peak power density of 1.112 W cm−2 and an electrolysis current density of −1.257 A cm−2 at 1.3 V in 3% H2O wet air at 600°C, with a reasonable faradaic efficiency. Furthermore, the cells demonstrate excellent stability, sustaining 100 h of thermal cycling (400–600°C, 200°C h−1) in both fuel cell and electrolysis modes, with 600 h of stability in electrolysis mode (600°C, −0.5 to −2 A cm−2).

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2020

Exploring the Vibrational Side of Spin-Phonon Coupling in Single-Molecule Magnets via 161 Dy Nuclear Resonance Vibrational Spectroscopy

Synchrotron-based nuclear resonance vibrational spectroscopy (NRVS) using the Mossbauer isotope 161 Dy has been employed for the first time to study the vibrational properties of a single-molecule magnet (SMM) incorporating Dy III , namely [Dy(Cy3PO)(2)(H2O)(5)]Br-3•2 (Cy3PO)•2 H2O•2 EtOH. The experimental partial phonon density of states (pDOS), which includes all vibrational modes involving a displacement of the Dy III ion, was reproduced by means of simulations using density functional theory (DFT), enabling the assignment of all intramolecular vibrational modes. This study proves that 161 Dy NRVS is a powerful experimental tool with significant potential to help to clarify the role of phonons in SMMs.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Targeting Oxide Concentration in Tantalum Oxide-Fluoride Anions

The design of both molecular and non-molecular solid materials with specific properties fundamentally relies on the controlled synthesis of crystals with desired functional groups, bonding motifs, polarity, chirality, and more. To this end, fluoride and oxide-fluoride anions have been utilized as basic building units (BBUs) in the synthesis of noncentrosymmetric racemic materials for their ability to create polar axes that facilitate the breaking of an inversion center as demonstrated in a series of compounds with [MF6]2- anions (M = Ti, Zr, Hf). Targeting an analog with a [TaOF5]2- anion, the phase space of (CuO, Ta2O5)/bpy/HF(aq)/H2O (bpy = 2,2′-bipyridine) was investigated and three new compounds with Cu-bpy cations and Ta-fluoride or Ta-oxyfluoride anions were synthesized: [Cu(bpy)2][TaF6], [Cu(bpy)2][Ta2OF10], and [Cu(bpy)F(H2O)2]2[TaF7]∙H2O with the anions [TaF6]-, [Ta2OF10]2-, and [TaF7]2-, respectively. The formation of these anions was found to be a product of both the concentration of hydrofluoric acid in solution and the ratio of metal-oxide starting materials to ligand. This work contributes to the understanding of mixed anion formation in the solid state.

Kamp, Kendall R.↗
DOE OSTI2022

Two Distinct Cu(II)-V(IV) Superexchange Interactions with Similar Bond Angles in a Triangular ?CuV2? Fragment

The strength and sign of superexchange interactions are often predicted on the basis of the bond angles between magnetic ions, but complications may arise in situations with a nontrivial arrangement of the magnetic orbitals. We report on a novel molecular tetramer compound [Cu(H2O)dmbpy]2[V2O2F8] (dmbpy = 4,4 '-dimethyl-2,2 ' bipyridyl) that is composed of triangular "CuV2" fragments and displays a spin gap behavior. By combining first-principles calculations and electronic models, we reveal that superexchange Cu-V interactions carry drastically diHerent coupling strengths along two Cu-F-V pathways with comparable bond angles in the triangular "CuV2" fragment. Counterintuitively, their strong disparity is found to originate from the restricted symmetry of the half-filled Cu dx2-y2 orbital stabilized by the crystal field, leading to one dominating antiferromagnetic Cu-V coupling in each fragment. We revisit the magnetic properties of the reported spin-gapped chain compound [enH2]Cu(H2O)2[V2O2F8] (enH2 = ethylene diammonium) containing similar triangular "CuV2" fragments, and the magnetic behavior of the molecular tetramer and the chain compounds is rationalized as that of weakly coupled spin dimers and spin trimers, respectively. This work demonstrates that fundamentally diHerent magnetic couplings can be observed between magnetic ions with similar bond angles in a single spin motif, thus providing a strategy to introduce various exchange interactions combined with low dimensionality in heterometallic Cu(II)-V(IV) compounds.

Complexes↗
DOE OSTI2021

The many-body expansion for aqueous systems revisited: II. Alkali metal and halide ion – water interactions

We present a detailed study of the Many-Body Expansion (MBE) for alkali metal and halide ion-water interactions and quantify the effect of these ions on the strength of the surrounding aqueous hydrogen bonding environment. Building on our previous work on neutral water clusters [J. P. Heindel and S. S. Xantheas, J. Chem. Theor. Comput. 16 (11), 6843–6855 (2020)], we carry out the complete MBE for ion-water clusters, Z+/-(H2O)9, where Z = Li+, K+, Cs+, Cl-, Br-, I- and compare with the results for (H2O)10. The 2-B ion-water (I-W) interaction represents a larger percentage of the total cluster binding energy compared to a pure water cluster of the same size with the total 3-B term being smaller and of opposite sign (repulsive) whereas higher order terms are essentially negligible. The same oscillating behavior around zero for MBE terms higher than the 5-B with basis set that was reported for water clusters is also observed for the ion-water clusters considered with Basis Set Superposition Error (BSSE) corrections amending this like in the water cluster case. A remarkable, linear anti-correlation between the total 2-B ion-water and the total 2-B and 3-B water-water interactions is found, quantifying the effect of the different ions in disrupting and altering (weakening) the neighboring hydrogen bonded water network. Our results suggest a universal behavior of the two different families of ions (alkali metals and halides) for both the correlations of the various components of the total binding energies as well as the estimate of the 2-B BSSE correction which is reported to follow a common profile for ion-water and water-water interactions when cast in terms of reduced distances and energies. We expect our insights into the nature of BSSE will be important for future ab initio based, many-body molecular dynamics studies.

ion-water interactions, water-water interaction, m↗