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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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Bimetallic NiCu catalysts supported on a Metal-Organic framework for Non-oxidative ethanol dehydrogenation

Non-oxidative ethanol dehydrogenation is a promising route to produce acetaldehyde and hydrogen from sustainable feedstock. Bimetallic NiCu catalysts have shown high efficiency and selectivity for this chemical transformation. In this study, we leverage the high porosity and uniform catalyst deposition sites on a Zr-based metal–organic framework (MOF) catalyst support, NU-1000, to understand how the changes in Cu:Ni ratio affects the reactivity for non-oxidative ethanol dehydrogenation. We found that increasing the Ni 2+ concentration significantly reduces the activation energy of the reaction due to the role of Ni 2+ in suppressing the onset of Cu reduction. Furthermore, this study illustrates how MOFs can be used as catalyst supports to fine-tune the catalyst compositions and understand their effect on the overall catalytic performances.

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

Promoting the cleavage of C-O bonds at the interface between a metal oxide cluster and a Co(0001) support

As a first step toward the rational design of Co-based catalysts with a higher activity and selectivity, we determine how one can activate a C-O bond at the interface between a metal oxide cluster and a Co(0001) support. The hypothesis here is that the metal ions in metal oxide clusters on a Co(0001) support enhance the adsorption of CO and weaken the C-O bond strength, which can then facilitate the dissociation of the CO reactant. To test this hypothesis, we developed three computational models of Ti4O8/Co(0001), Zr4O8/Co(0001), and Mn8O8/Co(0001). We quantify the CO adsorption behavior at the interface sites between an oxide cluster and the Co(0001) support as well as the corresponding IR spectra. We correlate the computed CO stretch frequencies with their CO adsorption energies, as well as the CO stretch frequency with the C-O bond length, and related these findings to the changes in the chemical bonding in the bound CO. The interface is the most favorable site for CO adsorption. Adsorption results in an increase of the C-O bond length and a decrease in its vibrational frequency. From a chemical bonding analysis, the bond order in CO at this site drops from 3 (in the gas phase) to 1. This decrease in bond order is a necessary precursor stage for CO dissociation. The experimental measurements of the corresponding FTIR spectra support this point. The favorability of CO adsorption at the interface sites is due to an electron transfer from the metal ion in the metal oxide cluster to the O atom in CO. We establish a linear relationship between C-O bond length and CO frequency and this relationship is found to be independent of the support, type of metal oxide cluster, or the adsorption site.

Fischer-Tropsch Synthesis, Heterogeneous Catalysis↗
DOE OSTI2022

AMPED EFRC: Alliance for Molecular PhotoElectrode Design for Solar Fuels

Inspired by natural photosynthesis, the mission of the AMPED EFRC was to develop the fundamental molecular basis for solar-driven water oxidation and carbon dioxide reduction catalysis with dye-sensitized photoelectrodes. From 2014-2022, the Center advanced the state-of-the-art in molecule-decorated photoanodes for water oxidation and broke new ground in the development of photocathodes for CO 2 reduction. A collaborative approach brought together experts in inorganic synthesis, organometallic catalysis, interfacial materials synthesis, photoelectrochemistry, and time-resolved dynamics to address by Grand Challenges in the 2007 DOE BESAC report. Since 2009, the UNC EFRC has published 314 peer-reviewed journal articles, and 2 book chapters. More specifically there were 146 peer-reviewed publications,1-146 during the 2014-20 funding cycle, with 80% supported solely by the EFRC, and about half resulting from collaborations among multiple PIs. Three major scientific research areas emerged from AMPED that are described below with details of the most impactful advances for solar energy research.

14 SOLAR ENERGY↗
DOE OSTI2024

Stabilization and manipulation of highly concentrated copper single atoms by high entropy oxides

Facile and controllable methodologies capable of providing single atom catalysts (SACs) with high-density active metal sites and sintering-resistance under harsh conditions are highly desired and grand challenges in heterogeneous catalysis. Herein, the entropy effect was leveraged to stabilize and manipulate the electronic properties of copper SACs. The as-developed ultrasonication-driven approach could integrate highly concentrated Cu SAs within the lattice of fluorite-structured high entropy oxide (HEFO) under ambient conditions (CuO-HEFO). The dual benefits from the high entropy effect of the support and the in-situ lattice engineering led to the generation of abundant Cu 1+ species and oxygen defects, together with ultra-high stability and sintering-resistance under extremely harsh conditions. This was confirmed by deploying non-high entropy support (CuO-CeO 2 ) or Cu sites located on the surface of HEFO (CuO@HEFO). In conclusion, the catalytic activity of CuO-HEFO surpassed that of CuO-CeO 2 and CuO@HEFO in CO oxidation together with well-maintained long-term stability and resistance to gas impurities.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Precision Structure Engineering of High-Entropy Oxides under Ambient Conditions

High-entropy oxides (HEOs) have unveiled a unique frontier in the realm of heterogeneous catalysis, taking advantage of the entropic effect and increased complexities to deliver ultrahigh stability and large tuning capability. However, current HEO synthesis mainly relies on high-temperature annealing approaches affording HEOs possessing no or low surface area, inferior active site exposure efficiency, and low controllability over the structure tuning. The grand challenge lies in producing high-quality HEO catalysts with high active site utilization efficiency, which relies on precision structure engineering, preferably under mild conditions. In this work, an in situ lattice engineering approach was developed to afford a supported HEO catalyst under ambient conditions. The HEO compositions (CuCoFeNiMnO x ) were uniformly integrated into the lattice of CeO 2 driven by cavitation-induced nucleation being generated via ultrasonication. The as-afforded catalysts were featured by high surface area, atomically dispersed HEO compositions, active redox properties, abundant oxygen vacancies (O V ), antiagglomeration, and high phase stability under harsh conditions. Compared with the ex situ introduction of HEO on the surface, the in situ method provides dual benefits to maintain the dispersity of HEO via entropic and lattice confinement effects. Engineering the complex HEO within the lattice of fluorite-structured CeO 2 also yields abundant defects (e.g., O V ) and active metal sites with strong reducing properties (e.g., Ce 3+ and Cu + ), which greatly improves the activity of the lattice oxygen and tunability of the adsorption behavior of the guest molecules, especially in the presence of impurities (e.g., water and propane). The catalytic performance of the supported HEO catalyst in oxidative procedures surpasses the pure dense phase HEO as well as the ex situ-generated catalysts. Further, the synthesis approach being developed in this work, together with the fundamental understanding in structure evolution and reaction mechanism, showcases a facile pathway under ambient conditions to generate stable catalysts capable of maintaining structural robustness in high-temperature conditions while delivering enhanced catalytic performance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Dynamic control and quantification of active sites on ceria for CO activation and hydrogenation

Ceria (CeO 2 ) is a widely used oxide catalyst, yet the nature of its active sites remains elusive. This study combines model and powder catalyst studies to elucidate the structure-activity relationships in ceria-catalyzed CO activation and hydrogenation. Well-defined ceria clusters are synthesized on planar CeO 2 (111) and exhibit dynamic and tunable ranges of Ce coordination numbers, which enhance their interaction with CO. Reduced ceria clusters (e.g., Ce 3 O 3 ) bind CO strongly and facilitate its dissociation, while near-stoichiometric clusters (e.g., Ce 3 O 7 ) adsorb CO weakly and promote oxidation via carbonate formation. Unlike planar ceria surfaces, supported ceria clusters exhibit dynamic properties and enhanced catalytic activity, that mimic those of powder ceria catalysts. Insight from model studies provide a method to quantify active sites on powder ceria and guide further optimization of ceria catalysts for syngas conversion. This work marks a leap toward model-guided catalyst design and highlights the importance of site-specific catalysis.

03 NATURAL GAS↗
DOE OSTI2024

Facile Access to Organostibines via Selective Organic Superbase Catalyzed Antimony‐Carbon Protonolysis

The selective formation of antimony-carbon bonds via organic superbase catalysis under metal- and salt-free conditions is reported. Here, this novel approach utilizes electron-deficient stibine, Sb(C 6 F 5 ) 3 , to give upon base-catalyzed reactions with weakly acidic aromatic and heteroaromatic hydrocarbons access to a range of new aromatic and heteroaromatic stibines, respectively, with loss of C 6 HF 5 . Also, the significantly less electron-deficient stibines, Ph 2 SbC 6 F 5 and PhSb(C 6 F 5 ) 2 smoothly underwent base-catalyzed exchange reactions with a range of terminal alkynes to generate the stibines of formulae PhSb(C≡CPh) 2 , and Ph 2 SbC≡CR [R=C 6 H 5 , C 6 H 4 -NO 2 , COOEt, CH 2 Cl, CH 2 NEt 2 , CH 2 OSiMe 3 , Sb(C 6 H 5 ) 2 ], respectively. These formal substitution reactions proceed with high selectivity as only the C 6 F 5 groups serve as a leaving group to be liberated as C 6 HF 5 upon formal proton transfer from the alkyne. Kinetic studies of the base-catalyzed reaction of Ph 2 SbC 6 F 5 with phenyl acetylene to form Ph 2 SbC≡CPh and C 6 HF 5 suggested the empirical rate law to exhibit a first-order dependence with respect to the base catalyst, alkyne and stibine. DFT calculations support a pathway proceeding via a concerted σ-bond metathesis transition state, where the base catalyst activates the Sb-C 6 F 5 bond sequence through secondary bond interactions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Systems-To-Atoms (S2A): enabling hydrogen for climate security

The project addresses a critical gap in hydrogen infrastructure by integrating system-level energy models with atomic-scale material simulations in a unified Systems-to-Atoms (S2A) framework. The motivation stems from the need to develop efficient, cost-effective, and durable hydrogen transport and utilization technologies to support decarbonization of hard-to-electrify sectors such as heavy-duty transportation. Current system models lack awareness of material performance mechanisms, while material-scale models do not account for system-level usage and variability. To bridge this divide, the team developed a co-simulation capability linking techno-economic analyses, reactor/process-flow modeling, and molecular-scale catalysis simulations. Applied to hydrogen delivery in California, the framework enabled comparative evaluations of compressed, cryogenic, and liquid organic hydrogen carrier (LOHC) pathways, highlighting how catalyst operation and unit process efficiency influence overall performance. The results demonstrate that no single material or transport mode is universally optimal; instead, heterogeneous solutions tuned to specific operational contexts deliver better performance. The project delivers a new capability for cross-scale material co-design, advancing hydrogen infrastructure readiness and informing DOE and LLNL missions in climate and energy resilience.

organic↗
DOE OSTI2026

Adsorption, charge transfer and a coverage-driven transition of alkali metals on rutile TiO 2 (110)

The interaction of alkali metals with metal oxide surfaces is central to tuning surface reactivity in heterogeneous catalysis and photocatalysis. Here we present a comprehensive DFT+U study of the adsorption of alkali metals (Li, Na, K, Rb, Cs) on the (110) surface of rutile TiO 2 . At low coverage (θ = 1/8), all alkali metals bind preferentially to bridging oxygen sites with adsorption energies in the range −4.06 to −3.33 eV, transferring nearly one full electron (0.92–0.99 |e|) to the substrate and inducing Ti 4+ → Ti 3+ reduction. The excess charge localizes preferentially at subsurface Ti sites in the form of small polarons. Diffusion barriers indicate facile motion along bridging-oxygen rows, whereas inter-row hopping is strongly hindered. Coverage effects were examined systematically for potassium: adsorption energy and charge transfer per K atom decrease monotonically with increasing θ. Strikingly, a sharp energy discontinuity occurs between θ = 4/8 and θ = 5/8 (ΔE ≈ 1 eV per atom), which we identify as a coverage-driven structural transition arising from steric packing constraints and enhanced K–K electrostatic repulsion once every (1×1) surface cell is occupied. This structural transition perfectly correlates with a dramatic drop in the work function down to an ultra-low minimum of 0.84 eV at θ=5/8, followed by a metallization- driven recovery at higher coverages. Ab initio molecular dynamics simulations confirm zigzag K arrangements at moderate coverage (θ = 1/3), while at high coverage (θ = 2/3) short-range K–K correlations emerge without long-range order. These results provide atomistic insight into the structure–activity relationships underlying alkali promotion effects on oxide-supported catalysts.

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

Towards the Accurate Thermodynamic Characterization of Enzyme Reaction Mechanisms

We employed QM/MM molecular dynamics (MD) simulations to characterize the rate-limiting step of the glycosylation reaction of pancreatic α-amylase with combined DFT/molecular dynamics methods (PBE/def2-SVP : AMBER). Upon careful choice of four starting active site conformations based on thorough reactivity criteria, Gibbs energy profiles were calculated with umbrella sampling simulations within a statistical convergence of 1 -2 kcal · mol -1 . Nevertheless, Gibbs activation barriers and reaction energies still varied from 11.0 to 16.8 kcal · mol -1 and -6.3 to +3.8 kcal · mol -1 depending on the starting conformations, showing that despite significant state-of-the-art QM/MM MD sampling (0.5 ns/profile) the result still depends on the starting structure. In conclusion, the results supported the one step dissociative mechanism of Asp197 glycosylation preceded by an acid-base reaction by the Glu233, which are qualitatively similar to those from multi-PES QM/MM studies, and thus support the use of the latter to determine enzyme reaction mechanisms.

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

Treasuring trash: Pt/SrTiO 3 catalysts process plastic waste into high-value materials

Single-use plastics are ubiquitous throughout modern society because they have properties that make them desirable in a wide variety of applications, including low cost of production, high thermal and chemical stability, and tunable mechanical properties. Several of the recycling methods currently used to process single-use plastic waste, such as mechanical recycling and pyrolysis, do not selectively process plastic materials into uniform products, as would be advantageous for repurposing these materials in pursuit of a circular economy. Catalytic hydrogenolysis, whereby C–C bonds in polymers are broken over a supported catalyst in the presence of H 2 , is a promising approach to converting plastics into value-added products that can be sold commercially without further purification. Here, in this account, we present some recent advances in polyolefin hydrogenolysis, with a focus on Pt nanoparticles on SrTiO 3 nanocuboid supports (Pt/STO). Current developments in this field, general challenges, and future directions are discussed.

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

The Development of Catalysts for Upgrading of Pyrolysis Vapor for Refinery Feedstocks and Intermediates: Cooperative Research and Development, CRADA Number CRD-12-00497 (Final Report)

Fast pyrolysis of biomass with vapor phase upgrading (VPU) can produce refinery feedstocks or intermediates that can meet the Department of Energy’s goal of cost-competitive hydrocarbon fuels by 2017. A key technical barrier for this technology is the lack of selective, cost effective catalysts that can produce high yields of fuel-appropriate hydrocarbons from the pyrolysis vapors. In overcoming this barrier, it will be important to engage leading catalyst development companies to devote their resources and expertise to the development of these materials. Thus, we propose a Cooperative Research and Development Agreement (CRADA) between the National Renewable Energy Laboratory (NREL), a world leader in biomass pyrolysis research and Johnson Matthey (JM), a world leader in the production of advanced catalyst materials to develop and test novel catalysts for efficient VPU. Through its Intercat Inc. subsidiary in Savannah, Ga., Johnson Matthey is internationally recognized as a leader in zeolite-based vapor phase upgrading in refinery duties and an emerging developer of biomass conversion technologies. The research and development efforts described in the proposed work will build upon existing collaborations between NREL and JM and play to the strengths of both institutions. NREL will analyze the composition of pyrolysis vapors as an input to catalyst design, screen and test catalysts, characterize the resulting oil and conduct techno-economic analysis. Catalyst samples will be produced and funded by JM. JM will design and synthesize catalysts, characterize fresh and used catalysts and develop catalyst supports needed to achieve commercially meaningful lifetimes. The project will span catalyst development and testing from the fundamental stage using quantum mechanical modeling and chemical reaction analysis to catalyst screening to integrated pilot studies.

09 BIOMASS FUELS↗
DOE OSTI2022

Magnetically recyclable nanocomposites via lanthanide-based MOFs grown on natural sea sponge: Screening hydrogenation of nitrophenol to aminophenol

Catalysts have played a significant role in chemical industries and received significant attention as a result. Unfortunately, many common catalytic systems are comprised of a small number of elemental species or use similar synthetic strategies, which potentially limit innovation in areas such as the discovery of new transformations. Metal-organic frameworks (MOFs) have been established as versatile materials employed in various applications that include catalysis; however, the majority of MOFs have been synthesized using transition metal building blocks, possibly hindering advances towards innovative materials with unique properties. Here this work reports the synthesis of MOFs based on lanthanide elements (Ln = Ce, Gd, La, and Sm), which demonstrate great potential yet are often overlooked. The Ln-based MOFs were grown in situ on natural sea sponge supports and Fe ion containing solution, followed by a thermal carbonization treatment to generate FeLn metal nanoparticles (NPs) embedded on carbon support (FeLn@C). These nanostructured products exhibited good crystallinity and well-confined particle sizes. We then demonstrate that these hybrid materials can be used as effective heterogeneous nanocatalysts for the hydrogenation of nitrophenol to aminophenol in aqueous media. Besides, FeLn@C catalysts had a magnetic property due to Fe atoms in the NPs, which can be mechanically separated out from the aqueous solution since the catalysts are magnetically attracted to the external magnets. This magnetic recyclability combined with the usage of the natural materials highlight the importance of sustainability in the design of Ln-based MOFs and their catalytic applications.

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

Inelastic Neutron Scattering Observation of Plasma-Promoted Nitrogen Reduction Intermediates on Ni/γ-Al 2 O 3

Plasma-assisted catalysis is an emerging technology for the atmospheric pressure and low bulk gas temperature synthesis of ammonia from molecular nitrogen and hydrogen. Direct evidence for plasma-induced surface reaction intermediates relevant to ammonia production, including surface hydrides and NH x (x = 1, 2, 3) species, has remained elusive. In this work, we report inelastic neutron scattering (INS) observations of alumina-supported Ni particles after treatment with N 2 and H 2 plasmas. INS experiments reveal the presence of NH x species and hydrides on Ni sites after exposure to sequential N 2 and H 2 plasma treatments. By separating exposure, we exclude the presence of plasma-phase reactions and demonstrate that these species are generated through plasma-facilitated surface reactions. Computed synthetic INS spectra of NH 3 , NH 2 and NH adsorbates on Ni support the experimental assignments of surface intermediates. The results directly implicate plasma stimulation of dinitrogen in generation of surface-bound nitrogen that participates in further hydrogenation reactions driven either thermally or with H 2 plasma.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Substituents effects on the electrocatalytic CO 2 reduction by cobalt corroles in solution

Electrochemical CO 2 reduction catalysis with cobalt corrole complexes in solution is reported. Corroles have attracted attention as contracted and trianionic tetrapyrrolic macrocycles that can be compared to leading porphyrin catalysts for CO 2 reduction, but most studies focus on heterogenized systems with poorly defined electrochemical responses. Electrochemical studies of cobalt corroles bearing axial triphenylphosphine ligands to ensure solubility are reported. The voltammetry provides mechanistic insights supporting CO 2 activation after the formal Co II /Co I reduction. The series of cobalt complexes, including a newly designed corrole with mixed perfluorophenyl/ortho-dimethoxyphenyl substituent pattern, provide evidence for electron-rich catalysts having stronger interactions with CO 2 . The primary product of CO 2 reduction is CO, formed at a rate of ca. 90 s −1 .

Kumar, Sachin [Technion–Israel Institute of Techno↗