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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Coordination environment tuning of nickel sites by oxyanions to optimize methanol electro-oxidation activity

To achieve zero-carbon economy, advanced anode catalysts are desirable for hydrogen production and biomass upgrading powered by renewable energy. Ni-based non-precious electrocatalysts are considered as potential candidates because of intrinsic redox attributes, but in-depth understanding and rational design of Ni site coordination still remain challenging. Here, we perform anodic electrochemical oxidation of Ni-metalloids (NiP x , NiS x , and NiSe x ) to in-situ construct different oxyanion-coordinated amorphous nickel oxyhydroxides (NiOOH-TO x ), among which NiOOH-PO x shows optimal local coordination environment and boosts electrocatalytic activity of Ni sites towards selective oxidation of methanol to formate. Experiments and theoretical results demonstrate that NiOOH-PO x possesses improved adsorption of OH* and methanol, and favors the formation of CH 3 O* intermediates. The coordinated phosphate oxyanions effectively tailor the d band center of Ni sites and increases Ni-O covalency, promoting the catalytic activity. This study provides additional insights into modulation of active-center coordination environment via oxyanions for organic molecules transformation.

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

Arsenite oxyanions affect CeO 2 nanoparticle dissolution and colloidal stability

While highly reactive cerium oxide nanoparticles (CeO 2 NPs) are widely used in industry, their transport in aquatic systems is not well understood. To fill this knowledge gap, the interactions of CeO 2 NPs with arsenite (As 3+ ), a toxic metalloid and potential co-present contaminant, were investigated with respect to CeO 2 NP colloidal stability, dissolution, and surface redox reactions. Arsenite showed distinctive effects at different concentrations, with a high As 3+ concentration (10 –4 M) inducing 90% of CeO 2 NPs to settle from solution after 8 hours, while lower As 3+ concentrations (10 –5 or 10 –6 M) led to only 20% of CeO 2 NPs settling. The dissolution of NPs was most significant in the 10 –5 M As 3+ system owing to a lesser extent of aggregation, exposing more CeO 2 surface for dissolution. In the three As 3+ concentration systems, >97% of aqueous arsenic remained as As 3+ over 6 hours. On the NP surface, adsorbed As III was oxidized to As V , resulting in 58–70% of the adsorbed arsenic remaining as As III . Simultaneously Ce IV was reduced to Ce III , increasing Ce III on the CeO 2 NP surface from 17% (without arsenite) to 21–25% (with arsenite). Further mechanistic analyses revealed that the adsorption of arsenite was the main contributor to neutralizing the CeO 2 NP surface potential, enhancing particle sedimentation. These findings suggest that the fate and transport of CeO 2 NPs in our experimental systems are strongly affected by arsenite concentration and its adsorption on NPs. Here, the results also highlight the importance of the interplay between NP aggregation, oxidation, and dissolution in predicting the behaviors of CeO 2 NPs and associated toxic elements in aquatic systems.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Persistent arsenate–iron( iii ) oxyhydroxide–organic matter nanoaggregates observed in coal

Understanding how natural nanoaggregates of iron (Fe) and organic matter (OM), currently identified in organic rich soil or peat, interact with metals and metalloids is environmentally significant. Here, coal is also organic-rich and exemplifies anoxic sedimentary environments with Fe usually as pyrite and not oxides. Here, we analyze the local structure of Fe (6880–21 700 mg kg –1 ) and As (45–5680 mg kg –1 ) in representative Guizhou coal samples using X-ray absorption near-edge structure and extended X-ray absorption fine structure (XANES and EXAFS) to illustrate how Fe(III) and As(V) are preserved in coal formed from reduced, organic-rich precursors. Arsenic XANES indicates that >80% of As exists as As(V) with <14% of As associated with sulfides in 5 Guizhou coal samples, confirming published but unexplained results. An As–Fe shell at 3.25–3.29 Å in the As EXAFS suggests that this As(V) is adsorbed on Fe(III) oxyhydroxides as evidenced by Fe EXAFS in these coal samples. Significantly, lower Fe–Fe coordination numbers (CN) of 0.6–1.1 relative to those in 2-line ferrihydrite (CN = 1.6) and goethite (CN = 2.1) suggest that these Fe(III) oxyhydroxides are likely Fe–OM nanoaggregates protected by OM encapsulation and adsorption of arsenate. Such structurally stabilized composites of As(V)–Fe(III)–OM may be more widely distributed and allow oxidized As and Fe to persist in other organic-rich, reducing environments.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Multivalent optical cycling centers: towards control of polyatomics with multi-electron degrees of freedom

Optical control of polyatomic molecules promises new opportunities in precision metrology and fundamental chemistry, as well as quantum information and many-body science. Contemporary experimental and theoretical efforts have mostly focused on cycling photons via excitation of a single electron localized to an alkaline earth (group 2)-like metal center. In this paper, we consider pathways towards optical cycling in polyatomic molecules with multi-electron degrees of freedom, which arise from two or more cycling electrons localized to p-block post-transition metal and metalloid (group 13, 14, and 15) centers. Here, we characterize the electronic structure and rovibrational branching of several prototypical candidates using ab initio quantum chemical methods. Despite increased internal complexity and challenging design parameters, we find several molecules possessing quasi-closed photon cycling schemes with highly diagonal, visible and near-infrared transitions. Furthermore, we identify new heuristics for engineering optically controllable and laser-coolable polyatomic molecules with multi-electron cycling centers. Our results help elucidate the interplay between hybridization, repulsion, and ionicity in optically active species and provide new directions for using polyatomic molecules with complex electronic structure as a resource for quantum science and measurement.

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

Structural evolution in Au- and Pd-based metallic glass forming liquids and the case for improved molecular dynamics force fields

The results of a combined experimental and computational investigation of the structural evolution of Au 81 Si 19 , Pd 82 Si 18 , and Pd 77 Cu 6 Si 17 metallic glass forming liquids are presented. Electrostatically levitated metallic liquids are prepared, and synchrotron x-ray scattering studies are combined with embedded atom method molecular dynamics simulations to probe the distribution of relevant structural units. Metal–metalloid based metallic glass forming systems are an extremely important class of materials with varied glass forming ability and mechanical processibility. High quality experimental x-ray scattering data are in poor agreement with the data from the molecular dynamics simulations, demonstrating the need for improved interatomic potentials. The first peak in the x-ray static structure factor in Pd 77 Cu 6 Si 17 displays evidence for a Curie–Weiss type behavior but also a peak in the effective Curie temperature. In conclusion, a proposed order parameter distinguishing glass forming ability, 1/(S(T,q 1 )−1, shows a peak in the effective Curie temperature near a crossover temperature established by the behavior of the viscosity, T A .

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

From legacy contamination to watershed systems science: a review of scientific insights and technologies developed through DOE-supported research in water and energy security

Abstract Water resources, including groundwater and prominent rivers worldwide, are under duress because of excessive contaminant and nutrient loads. To help mitigate this problem, the United States Department of Energy (DOE) has supported research since the late 1980s to improve our fundamental knowledge of processes that could be used to help clean up challenging subsurface problems. Problems of interest have included subsurface radioactive waste, heavy metals, and metalloids (e.g. uranium, mercury, arsenic). Research efforts have provided insights into detailed groundwater biogeochemical process coupling and the resulting geochemical exports of metals and nutrients to surrounding environments. Recently, an increased focus has been placed on constraining the exchanges and fates of carbon and nitrogen within and across bedrock to canopy compartments of a watershed and in river–floodplain settings, because of their important role in driving biogeochemical interactions with contaminants and the potential of increased fluxes under changing precipitation regimes, including extreme events. While reviewing the extensive research that has been conducted at DOE’s representative sites and testbeds (such as the Oyster Site in Virginia, Savannah River Site in South Carolina, Oak Ridge Reservation in Tennessee, Hanford in Washington, Nevada National Security Site in Nevada, Riverton in Wyoming, and Rifle and East River in Colorado), this review paper explores the nature and distribution of contaminants in the surface and shallow subsurface (i.e. the critical zone) and their interactions with carbon and nitrogen dynamics. We also describe state-of-the-art, scale-aware characterization approaches and models developed to predict contaminant fate and transport. The models take advantage of DOE leadership-class high-performance computers and are beginning to incorporate artificial intelligence approaches to tackle the extreme diversity of hydro-biogeochemical processes and measurements. Recognizing that the insights and capability developments are potentially transferable to many other sites, we also explore the scientific implications of these advances and recommend future research directions.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Predictive design of novel nickel-based superalloys beyond Haynes 282. Final Report FWP-AL-19-510-097

Nickel-based superalloys are in great demand for harsh-service conditions involving high temperatures and oxidative environments. Haynes 282 stands out due to its excellent high-temperature properties and easy fabricability. However, the upper usage temperature of Haynes 282 is limited due to its relatively low liquidus temperature. Through high-fidelity density functional theory calculations and high-throughput experiments, new compositions that show higher liquidus temperature and higher strength are explored. While maintaining processability, the newly designed alloy shows improved strength and ductility at room temperature and better oxidation resistance up to 800°C. The new compositions showcase a minor change in the refractory and metalloid content can have a significant impact on the mechanical and oxidation performance of superalloys.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Arsenic Exposure Causes Global Changes in the Metalloproteome of Escherichia coli

Arsenic is a toxic metalloid with differential biological effects, depending on speciation and concentration. Trivalent arsenic (arsenite, AsIII) is more toxic at lower concentrations than the pentavalent form (arsenate, AsV). In E. coli, the proteins encoded by the arsRBC operon are the major arsenic detoxification mechanism. Our previous transcriptional analyses indicate broad changes in metal uptake and regulation upon arsenic exposure. Currently, it is not known how arsenic exposure impacts the cellular distribution of other metals. This study examines the metalloproteome of E. coli strains with and without the arsRBC operon in response to sublethal doses of AsIII and AsV. Size exclusion chromatography coupled with inductively coupled plasma mass spectrometry (SEC-ICPMS) was used to investigate the distribution of five metals (56Fe, 24Mg, 66Zn, 75As, and 63Cu) in proteins and protein complexes under native conditions. Parallel analysis by SEC-UV-Vis spectroscopy monitored the presence of protein cofactors. Together, these data reveal global changes in the metalloproteome, proteome, protein cofactors, and soluble intracellular metal pools in response to arsenic stress in E. coli. This work brings to light one outcome of metal exposure and suggests that metal toxicity on the cellular level arises from direct and indirect effects.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Mesoporous materials and processes for preparation thereof

A process for preparing a mesoporous material, e.g., transition metal oxide, sulfide, selenide or telluride, Lanthanide metal oxide, sulfide, selenide or telluride, a post-transition metal oxide, sulfide, selenide or telluride and metalloid oxide, sulfide, selenide or telluride. The process comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic or lyotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to form the mesoporous material. A mesoporous material prepared by the above process. A method of controlling nano-sized wall crystallinity and mesoporosity in mesoporous materials. The method comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic or lyotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to control nano-sized wall crystallinity and mesoporosity in the mesoporous material. Mesoporous materials and a method of tuning structural properties of mesoporous materials.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Protective anode coatings for high energy batteries

Materials for coating a metal anode in a high energy battery, anodes coated with the materials, and batteries incorporating the coated anodes are provided. Also provided are batteries that utilize the materials as electrolytes. The coatings, which are composed of binary, ternary, and higher order metal and/or metalloid oxides, nitrides, fluorides, chlorides, bromides, sulfides, and carbides limit the reactions between the electrolyte and the metal anode in a battery, thereby improving the performance of the battery, relative to a battery that employs a bare anode.

Hegde, Vinay Ishwar↗
DOE OSTI2022

Cathode additives for lithium-ion batteries

In some implementations, a cathode is formed by (1) providing a cathode additive including (a) a matrix including a lithium compound, and (b) metal nanostructures embedded in the matrix; and (2) combining the cathode additive with a cathode active material to form a mixture. In other implementations, a cathode is formed by (1) providing a cathode additive including a compound of lithium and at least one non-metal or metalloid; and (2) combining the cathode additive with a cathode active material to form a mixture.

25 ENERGY STORAGE↗
DOE OSTI2022

Protective anode coatings for high energy batteries

Materials for coating a metal anode in a high energy battery, anodes coated with the materials, and batteries incorporating the coated anodes are provided. Also provided are batteries that utilize the materials as electrolytes. The coatings, which are composed of binary, ternary, and higher order metal and/or metalloid oxides, nitrides, fluorides, chlorides, bromides, sulfides, and carbides limit the reactions between the electrolyte and the metal anode in a battery, thereby improving the performance of the battery, relative to a battery that employs a bare anode.

Hegde, Vinay Ishwar↗
DOE OSTI2023

System and method for optical fiber preform preparation via high-surface-area coating

The present disclosure relates to a method for forming a glass, ceramic or composite material. The method may involve initially forming a plurality of tubes and then performing a coating operation to coat the plurality of tubes with materials containing metal or metalloid elements, including inorganic compounds, organometallic compounds, or coordination complexes to form coated tubes. The method may further include performing at least one of a thermal operation or a thermochemical operation on the coated tubes to form a solid glass, ceramic, or composite structure with dimensions representing at least one of a rod or fiber.

Lange, Andrew↗
DOE OSTI2024

Calcium-metal alloy anode materials for reversible calcium-ion batteries

Calcium ion batteries are provided. The calcium ion batteries include a cathode, an alloying anode composed of one or more intermetallic calcium compounds in electrical communication with the cathode; and an electrolyte disposed between the anode and the cathode. The intermetallic calcium compounds are intermetallic compounds of calcium and transition metals and metalloids.

Yao, Zhenpeng↗
DOE OSTI2024

High temperature thermochemical energy storage materials

Disclosed are high enthalpy thermochemical energy storage materials that exhibit high thermal conductivity and stability at high temperature reaction conditions. Disclosed materials include hydride-based alloys that can undergo high temperature reversible hydrogenation/dehydrogenation reactions without phase change of any metal or metalloid components of the alloy. The materials undergo a reversible exothermic hydrogenation reaction to form a metal hydride and a ternary alloy that includes a high thermal conductivity metal that, in its pure state, would exhibit a phase change at the hydrogenation reaction conditions.

Ward, Patrick A.↗
DOE OSTI2021

The role of cysteine in tellurate reduction and toxicity

The tellurium oxyanion tellurate is toxic to living organisms even at low concentrations; however, its mechanism of toxicity is poorly understood. Here, we show that exposure of Escherichia coli K-12 to tellurate results in reduction to elemental tellurium (Te[0]) and the formation of intracellular reactive oxygen species (ROS). Toxicity assays performed with E. coli indicated that pre-oxidation of the intracellular thiol pools increases cellular resistance to tellurate-suggesting that intracellular thiols are important in tellurate toxicity. X-ray absorption spectroscopy experiments demonstrated that cysteine reduces tellurate to elemental tellurium. This redox reaction was found to generate superoxide anions. These results indicate that tellurate reduction to Te(0) by cysteine is a source of ROS in the cytoplasm of tellurate-exposed cells.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Facet-dependent electron transfer induces distinct arsenic reallocations on hematite

The interfacial electron transfer (ET) between electron shuttling compounds and iron (Fe) oxyhydroxides plays a crucial role in the reductive dissolution of Fe minerals and the fate of surface-bound arsenic (As). However, the impact of exposed facets of highly crystalline hematite on reductive dissolution and As immobilization is poorly understood. In this study, we systematically investigated the interfacial processes of the electron shuttling compound cysteine (Cys) on various facets of hematite and the reallocations of surface-bound As(III) or As(V) on the respective surfaces. Our results demonstrate that the ET process between Cys and hematite generates Fe(II) and leads to reductive dissolution, with more Fe(II) generated on {001} facets of exposed hematite nanoplates (HNPs). Reductive dissolution of hematite leads to significantly enhanced As(V) reallocations on hematite. Nevertheless, upon the addition of Cys, a raipd release of As(III) can be halted by its prompt re-adsorption, leaving the extent of As(III) immobilization on hematite unchanged throughout the course of reductive dissolution. This is due to that Fe(II) can form new precipitates with As(V), a process that is facet-dependent and influenced by water chemistry. Electrochemical analysis reveals that HNPs exhibit higher conductivity and ET ability, which is beneficial for reductive dissolution and As reallocations on hematite. In conclusion, these findings highlight the facet-dependent reallocations of As(III) and As(V) facilitated by electron shuttling compounds and have implications for the biogeochemical processes of As in soil and subsurface environments.

54 ENVIRONMENTAL SCIENCES↗