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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Ultra-stable and poison tolerant oxygen evolution activity enabled by surface In 2 O 3- x (OH) y of Co 3 In 2 S 2 large single crystals

Water is an earth-abundant source for clean hydrogen production via electrochemical water electrolysis (WE). However, the surface poisoning that occurs in aqueous electrolytes drastically deactivates the electrocatalytic performance of electrodes. Here, in this study, we report electrochemically formed In 2 O 3-x (OH) y on the surface of a large (1–1.5 mm long, 0.5–0.6 mm wide and 0.3–0.5 mm thick) single crystal of Weyl semimetal Co 3 In 2 S 2 (Co 3 In 2 S 2 /In 2 O 3-x (OH) y ) as an ultra-stable and poison tolerant electrode for the oxygen evolution reaction (OER) in 1 M KOH, addressing a bottleneck in WE. The OER activity of the powder form of Co 3 In 2 S 2 is limited by its aerophilic nature. Remarkably, the single-crystal electrodes maintained their high activity for a continuous operational period of 5 h in 1 M KOH electrolyte with/without 10 mM strong surface-poisoning ligands i.e., potassium cyanide, bipyridine, and ethylenediaminetetraacetate disodium salt. The electrodes exhibited stable OER activity for 1000 h at 100 mA cm -2 (1.73 V vs. RHE). The temperature-dependent OER polarization curves (10–70 °C) unambiguously revealed surface poisoning through the suppression of precatalytic Co-redox peaks on the bipyridine poisoned electrode, which led to the stabilization of surface Co-sites. The X-ray photoelectron spectroscopy analyses of pristine, poisoned and post-electrocatalytic single-crystal Co 3 In 2 S 2 electrodes revealed the existence of an In 2 O 3-x (OH) y surface phase, which could be the potential heterostructure for the origin of ultra-stable and poison tolerant OER activity.

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

Ultrafast dynamics of CN radical reactions with chloroform solvent under vibrational strong coupling

Polariton chemistry may provide a new means to control molecular reactivity, permitting remote, reversible modification of reaction energetics, kinetics, and product yields. A considerable body of experimental and theoretical work has already demonstrated that strong coupling between a molecular vibrational mode and the confined electromagnetic field of an optical cavity can alter chemical reactivity without external illumination. However, the mechanisms underlying cavity-altered chemistry remain unclear in large part because the experimental systems examined previously are too complex for detailed analysis of their reaction dynamics. Here, we experimentally investigate photolysis-induced reactions of cyanide radicals with strongly-coupled chloroform (CHCl 3 ) solvent molecules and examine the intracavity rates of photofragment recombination, solvent complexation, and hydrogen abstraction. Here we use a microfluidic optical cavity fitted with dichroic mirrors to facilitate vibrational strong coupling (VSC) of the C–H stretching mode of CHCl 3 while simultaneously permitting optical access at visible wavelengths. Ultrafast transient absorption experiments performed with cavities tuned on- and off-resonance reveal that VSC of the CHCl 3 C–H stretching transition does not significantly modify any measured rate constants, including those associated with the hydrogen abstraction reaction. This work represents, to the best of our knowledge, the first experimental study of an elementary bimolecular reaction under VSC. We discuss how the conspicuous absence of cavity-altered effects in this system may provide insights into the mechanisms of modified ground state reactivity under VSC and help bridge the divide between experimental results and theoretical predictions in vibrational polariton chemistry.

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

Modelling CN Zeeman effect observations of the envelopes of a low-mass protostellar disc and a massive protostar

We use the POLARIS radiative transfer code to produce simulated circular polarization Zeeman emission maps of the cyanide (CN) J = 1–0 molecular line transition for two types of protostellar envelope magnetohydrodynamic simulations. Our first model is a low-mass disc envelope system (box length L = 200 au), and our second model is the envelope of a massive protostar (L = 104 au) with a protostellar wind and a CN-enhanced outflow shell. We compute the velocity-integrated Stokes I and V, as well as the implied V/I polarization percentage, for each detector pixel location in our simulated emission maps. Our results show that both types of protostellar environments are in principle accessible with current circular polarization instruments, with each containing swaths of envelope area that yield percentage polarizations that exceed the 1.8 percent nominal sensitivity limit for circular polarization experiments with the Atacama Large Millimeter/submillimeter Array. In both systems, high-polarization (≳1.8 percent) pixels tend to lie at an intermediate distance away from the central star and where the line-centre opacity of the CN emission is moderately optically thin (τLC ~ 0.1–1). Furthermore, our computed V/I values scale roughly with the density-weighted mean line-of-sight magnetic field strength, indicating that Zeeman observations can effectively diagnose the strength of envelope-scale magnetic fields. We also find that pixels with large V/I are preferentially co-located where the absolute value of the velocity-integrated V is also large, suggesting that locations with favourable percentage polarization are also favourable in terms of raw signal.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2024

Direct HCN synthesis via plasma-assisted conversion of methane and nitrogen

Hydrogen cyanide (HCN) is synthesized from ammonia (NH 3 ) and methane (CH 4 ) at ~1200°C over a Pt catalyst. Ammonia synthesis entails several complex, highly emitting processes. Plasma-assisted HCN synthesis directly from CH 4 and nitrogen (N 2 ) could be pivotal for on-demand HCN production. Here, we evaluate the potential of dielectric barrier discharge (DBD) N 2 /CH 4 plasma for decentralized catalyst-free selective HCN production. We demonstrate a single-step conversion of methane and nitrogen to HCN with a 72% yield at <300°C. HCN is favored at low CH 4 concentrations with ethane (C 2 H 6 ) as the secondary product. We propose a first-principles microkinetic model with few electron impact reactions. The model accurately predicts primary product yields and elucidates that methyl radical (·CH 3 ) is a common intermediate in HCN and C 2 H 6 synthesis. Compared to current industrial processes, N 2 /CH 4 DBD plasma can achieve minimal CO 2 emissions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Performance Improvement of Lithium Metal Batteries Enabled By LiBF 3 CN as a New Electrolyte Additive

A newly synthesized electrolyte additive, lithium trifluoro(cyano) borate (LiBF 3 CN), has been investigated for electrochemical performance improvement of lithium metal batteries. The LiBF 3 CN has a structure where one fluorine atom of BF 4 – is substituted with a cyano group (–CN) prepared by the reaction of boron trifluoride etherate with lithium cyanide. The electrochemical performance in symmetric Li/Li cells and NCM523/Li cells is significantly improved upon the incorporation of LiBF 3 CN as an electrolyte additive into a carbonate-based electrolyte. Extensive characterization of the deposited lithium metal reveals that a thin (≈20 nm) and robust SEI composed of LiN x O y , Li 3 N and Li 2 O is formed by the reductive decomposition of the LiBF 3 CN additive, which plays an important role in decreasing the resistance and stabilizing lithium deposition/stripping. The insight into the substitution effect of a functional group obtained from this work provides guidance for the design of new electrolyte additives.

25 ENERGY STORAGE↗
DOE OSTI2020

Materials Data on BaNiN by Materials Project

BaNiN is Potassium Silver Cyanide-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to four N3- atoms to form distorted corner-sharing BaN4 tetrahedra. There are a spread of Ba–N bond distances ranging from 2.77–2.84 Å. In the second Ba2+ site, Ba2+ is bonded in a distorted rectangular see-saw-like geometry to four N3- atoms. There are a spread of Ba–N bond distances ranging from 2.81–3.02 Å. There are two inequivalent Ni1+ sites. In the first Ni1+ site, Ni1+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.80 Å) and one longer (1.84 Å) Ni–N bond length. In the second Ni1+ site, Ni1+ is bonded in a linear geometry to two equivalent N3- atoms. Both Ni–N bond lengths are 1.76 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to four Ba2+ and two equivalent Ni1+ atoms to form a mixture of distorted edge and corner-sharing NBa4Ni2 octahedra. The corner-sharing octahedra tilt angles range from 1–68°. In the second N3- site, N3- is bonded to four Ba2+ and two Ni1+ atoms to form a mixture of distorted edge and corner-sharing NBa4Ni2 octahedra. The corner-sharing octahedra tilt angles range from 0–68°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CoH9(CN2)3 by Materials Project

CoCo(NH3)6(CN)6 crystallizes in the trigonal R-3 space group. The structure is zero-dimensional and consists of three azane;cobalt molecules, three cobalt molecules, and eighteen hydrogen cyanide molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CrCoH18(CN2)6 by Materials Project

CrCo(NH3)6(CN)6 crystallizes in the trigonal R-3 space group. The structure is zero-dimensional and consists of three azane;cobalt molecules, three chrom molecules, and eighteen hydrogen cyanide molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C2N by Materials Project

C2N crystallizes in the cubic Pa-3 space group. The structure is zero-dimensional and consists of twenty-four hydrogen cyanide molecules and twenty-four methane molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CN by Materials Project

CN is alpha carbon monoxide-like structured and crystallizes in the orthorhombic Pbca space group. The structure is zero-dimensional and consists of eight hydrogen cyanide molecules. C3+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.17 Å. N3- is bonded in a single-bond geometry to one C3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag25(BiO6)3 by Materials Project

Ag25(BiO6)3 is Potassium Silver Cyanide-derived structured and crystallizes in the trigonal P-3 space group. The structure is three-dimensional. there are six inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a distorted linear geometry to two O2- atoms. There are one shorter (2.16 Å) and one longer (2.21 Å) Ag–O bond lengths. In the second Ag1+ site, Ag1+ is bonded in a linear geometry to two O2- atoms. There are one shorter (2.14 Å) and one longer (2.15 Å) Ag–O bond lengths. In the third Ag1+ site, Ag1+ is bonded in a linear geometry to two equivalent O2- atoms. Both Ag–O bond lengths are 2.13 Å. In the fourth Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Ag–O bond lengths are 2.58 Å. In the fifth Ag1+ site, Ag1+ is bonded in a linear geometry to two O2- atoms. Both Ag–O bond lengths are 2.17 Å. In the sixth Ag1+ site, Ag1+ is bonded in a linear geometry to two equivalent O2- atoms. Both Ag–O bond lengths are 2.11 Å. There are two inequivalent Bi+3.67+ sites. In the first Bi+3.67+ site, Bi+3.67+ is bonded in an octahedral geometry to six equivalent O2- atoms. All Bi–O bond lengths are 2.20 Å. In the second Bi+3.67+ site, Bi+3.67+ is bonded in an octahedral geometry to six O2- atoms. There are three shorter (2.27 Å) and three longer (2.46 Å) Bi–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Ag1+ and one Bi+3.67+ atom. In the second O2- site, O2- is bonded to three Ag1+ and one Bi+3.67+ atom to form distorted corner-sharing OAg3Bi tetrahedra. In the third O2- site, O2- is bonded to three Ag1+ and one Bi+3.67+ atom to form corner-sharing OAg3Bi tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaCN2 by Materials Project

BaCN2 is Potassium Silver Cyanide-derived structured and crystallizes in the trigonal R-3c space group. The structure is three-dimensional. Ba2+ is bonded to six equivalent N3- atoms to form a mixture of distorted edge and corner-sharing BaN6 pentagonal pyramids. There are a spread of Ba–N bond distances ranging from 2.78–2.91 Å. C4+ is bonded in a linear geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.24 Å. N3- is bonded in a 1-coordinate geometry to three equivalent Ba2+ and one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CrH9(CN2)3 by Materials Project

CrCr(NH3)6(CN)6 crystallizes in the trigonal R-3 space group. The structure is zero-dimensional and consists of three chromium molecules, eighteen hydrogen cyanide molecules, and three Cr(NH3)6 clusters. In each Cr(NH3)6 cluster, Cr3+ is bonded in an octahedral geometry to six equivalent N3- atoms. All Cr–N bond lengths are 2.11 Å. N3- is bonded in a distorted trigonal non-coplanar geometry to one Cr3+ and three H1+ atoms. There is two shorter (1.03 Å) and one longer (1.04 Å) N–H bond length. There are three 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.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HCN by Materials Project

C(CN)2CN2H4 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of eight hydrogen cyanide molecules, four methane molecules, and four methanediamine molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZnAs2C12(NF)12 by Materials Project

Zn(CN)6(CN)6(AsF6)2 crystallizes in the trigonal R-3 space group. The structure is zero-dimensional and consists of eighteen hydrogen cyanide molecules, six AsF6 clusters, and three Zn(CN)6 clusters. In each AsF6 cluster, As is bonded in an octahedral geometry to six F1- atoms. There is three shorter (1.77 Å) and three longer (1.78 Å) As–F bond length. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one As atom. In the second F1- site, F1- is bonded in a single-bond geometry to one As atom. In each Zn(CN)6 cluster, Zn2+ is bonded in an octahedral geometry to six equivalent N3- atoms. All Zn–N bond lengths are 2.15 Å. C+3.83+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.16 Å. N3- is bonded in a linear geometry to one Zn2+ and one C+3.83+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nb2O5 by Materials Project

Nb2O5 is Potassium Silver Cyanide-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are three inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 7–32°. There are a spread of Nb–O bond distances ranging from 1.80–2.37 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 6–16°. There are a spread of Nb–O bond distances ranging from 1.93–2.17 Å. In the third Nb5+ site, Nb5+ is bonded in a 4-coordinate geometry to six O2- atoms. There are a spread of Nb–O bond distances ranging from 1.80–2.49 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two Nb5+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Nb5+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Nb5+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two equivalent Nb5+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to two equivalent Nb5+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to two Nb5+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to four equivalent Nb5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te2AsCNF6 by Materials Project

CNAsTe2F6 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four hydrogen cyanide molecules and one AsTe2F6 sheet oriented in the (-1, 0, 2) direction. In the AsTe2F6 sheet, As3- is bonded in an octahedral geometry to six F1- atoms. There are a spread of As–F bond distances ranging from 1.76–1.80 Å. There are two inequivalent Te4+ sites. In the first Te4+ site, Te4+ is bonded in a 2-coordinate geometry to two equivalent Te4+ and one F1- atom. There are one shorter (2.70 Å) and one longer (2.71 Å) Te–Te bond lengths. The Te–F bond length is 3.12 Å. In the second Te4+ site, Te4+ is bonded in a 4-coordinate geometry to two equivalent Te4+ and two F1- atoms. There are one shorter (2.96 Å) and one longer (3.02 Å) Te–F bond lengths. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one As3- atom. In the second F1- site, F1- is bonded in a single-bond geometry to one As3- atom. In the third F1- site, F1- is bonded in a single-bond geometry to one As3- atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one As3- and two Te4+ atoms. In the fifth F1- site, F1- is bonded in a single-bond geometry to one As3- atom. In the sixth F1- site, F1- is bonded in a single-bond geometry to one As3- and one Te4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KC2IN2 by Materials Project

KC2N2I is Potassium Silver Cyanide-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded to six equivalent N3- atoms to form edge-sharing KN6 octahedra. There are two shorter (2.88 Å) and four longer (2.99 Å) K–N bond lengths. C3+ is bonded in a distorted single-bond geometry to one N3- and one I1- atom. The C–N bond length is 1.18 Å. The C–I bond length is 2.28 Å. N3- is bonded in a 4-coordinate geometry to three equivalent K1+ and one C3+ atom. I1- is bonded in a linear geometry to two equivalent C3+ atoms.

36 MATERIALS SCIENCE↗