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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Magnesium‐Mediated Electrochemical Synthesis of Ammonia

Metal-mediated electrochemical synthesis of ammonia (NH3) is a promising method to activate N2 at room temperature. While a Li-mediated approach has been optimized to produce NH3 at high current density and selectivity, Li's scarcity and its highly negative plating potential limit scalability and energy efficiency. Alternative mediators have been proposed, but only Ca has shown some promise, achieving ≈50% Faradaic efficiency (FE), though requiring voltages beyond -3 V. Here, we report a Mg-mediated nitrogen reduction reaction (Mg-NRR), where N2 is activated on Mg to form Mg3N2, followed by protolysis to release NH3 and regenerate Mg. A notable NH3 FE of 25.28 ± 3.80% is achieved at a current density of -45 mA cm-2, corresponding to an NH3 partial current density of -11.30 ± 1.77 mA cm-2 under 6 bar N2. Isotope-labeled experiments confirm that NH3 originates from N2, with similar FE (25.15 ± 1.01%). Importantly, NH3 production is demonstrated at a total cell potential as low as -3 V. This Li-free Mg-NRR system offers key advantages, including lower energy input and use of earth-abundant materials, making it a scalable route for sustainable NH3 synthesis.

Goyal, Ishita↗
DOE OSTI2022

Scalable Direct Recycling of Cathode Black Mass from Spent Lithium‐Ion Batteries

Abstract End of life (EoL) lithium‐ion batteries (LIBs) are piling up at an intimidating rate, which is alarming for environmental health. With further expected rapid growth of LIB use, the magnitude of spent battery accumulation is also expected to grow. LiNi x Co y Mn z O 2 (NCM) cathode materials are a dominant chemistry in high energy LIBs, and make up a huge portion of this waste accumulation. Direct recycling is one of the most promising ways to turn this waste to wealth, but has been limited to lab‐scale, due to lack of robustness, namely the tedious pretreatment required that involves toxic organic solvents. Herein, a process that integrates the pretreatment and relithiation of the cathode black mass is demonstrated. Cathode material from EoL electric vehicle (EV) batteries is treated in a 100 g per batch operation and the regenerated cathode active material demonstrates 100% electrochemical performance recovery, with 91% yield rate, and shows promise for further scale up. This process has the advantages of integration, scalability, and universality, which clears the barricade for direct recycling to move from lab to industry scale with considerable profitability.

Chemistry↗
DOE OSTI2023

Two-Step Chemical Looping Cycle for Renewable NH 3 Production Based on Non-Catalytic Co 3 Mo 3 N/Co 6 Mo 6 N Reactions

A two-step solar thermochemical looping cycle based on Co 3 Mo 3 N/Co 6 Mo 6 N reduction/nitridation reactions offers a pathway for green NH 3 production that utilizes concentrated solar irradiation, H 2 O, and air as feedstocks. The NH 3 production cycle steps both derive process heat from concentrated solar irradiation and encompass 1) the reduction of Co 3 Mo 3 N in H 2 to Co 6 Mo 6 N and NH 3 ; and 2) nitridation of Co 6 Mo 6 N to Co 3 Mo 3 N with N 2 . Co 3 Mo 3 N reduction/nitridation reactions are examined at different H 2 and/or N 2 partial pressures and temperatures. NH 3 production is quantified in situ using liquid conductivity measurements coupled with mass spectrometry (MS). Solid-state characterization is performed to identify a surface oxygen layer that necessitates the addition of H 2 during cycling to prevent surface oxidation by trace amounts of O 2 . H 2 concentrations of > 5% H 2 /Ar and temperatures >500 °C are required to reduce Co 3 Mo 3 N to Co 6 Mo 6 N and form NH 3 at 1 bar. Complete regeneration of Co 3 Mo 3 N from Co 6 Mo 6 N is achieved at conditions of 700 °C under 25–75% H 2 /N 2 . H 2 pressure-swings are observed to increase NH 3 production during Co 3 Mo 3 N reduction. In conclusion, the results represent the first comprehensive characterization of and definitive non-catalytic production of NH 3 via chemical looping with metal nitrides and provide insights for technology development.

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

Carbonic anhydrase textile structured packing for efficient CO 2 absorption in methyldiethanolamine solvent

Carbonic anhydrase (CA) is an attractive biodegradable catalyst for CO 2 absorption in solvent–based CO 2 capture. However, maintaining the stability of CA as a homogeneous component of the solvents is a challenge. Solvent regeneration temperature typically exceeds the enzyme thermal tolerance, which leads to CA deactivation. To reduce the need for frequent CA replenishment and to avoid inactive CA accumulation in the solvent, this work shows the benefits of an immobilization strategy where CA is fixed in a second–generation design of textile structured packing (CATSP–2) modules. The enzyme–immobilized packing showed 1.5 times better performance in CO 2 separation compared with traditional structured packing with a corresponding increased CO 2 loading in the rich solvent. The modules exhibited good CA activity retention of ~80% during the tests without any CA replenishment. As a result, applying CATSP–2 could potentially decrease the packing height and absorber column size for a lower cost per amount of CO 2 captured.

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

Anthraquinone Redox Relay for Dye‐Sensitized Photo‐electrochemical H 2 O 2 Production

Abstract Anthraquinone (AQ) redox mediators are introduced to metal‐free organic dye sensitized photo‐electrochemical cells (DSPECs) for the generation of H 2 O 2 . Instead of directly reducing O 2 to produce H 2 O 2 , visible‐light‐driven AQ reduction occurs in the DSPEC and the following autooxidation with O 2 allows H 2 O 2 accumulation and AQ regeneration. In an aqueous electrolyte, under 1 sun conditions, a water‐soluble AQ salt is employed with the highest photocurrent of up to 0.4 mA cm −2 and near‐quantitative faradaic efficiency for producing H 2 O 2 . In a non‐aqueous electrolyte, under 1 sun illumination, an organic‐soluble AQ is applied and the photocurrent reaches 1.8 mA cm −2 with faradaic efficiency up to 95 % for H 2 O 2 production. This AQ‐relay DSPEC exhibits the highest photocurrent so far in non‐aqueous electrolytes for H 2 O 2 production and excellent acid stability in aqueous electrolytes, thus providing a practical and efficient strategy for visible‐light‐driven H 2 O 2 production.

Sun, Jiaonan↗
DOE OSTI2020

A Strategy for Constructing Pore‐Space‐Partitioned MOFs with High Uptake Capacity for C 2 Hydrocarbons and CO 2

Abstract Introduction of pore partition agents into hexagonal channels of MIL‐88 type (acs topology) endows materials with high tunability in gas sorption. Here, we report a strategy to partition acs framework into pacs (partitioned acs) crystalline porous materials (CPM). This strategy is based on insertion of in situ synthesized 4,4′‐dipyridylsulfide (dps) ligands. One third of open metal sites in the acs net are retained in pacs MOFs; two thirds are used for pore‐space partition. The Co 2 V‐pacs MOFs exhibit near or at record high uptake capacities for C 2 H 2 , C 2 H 4 , C 2 H 6 , and CO 2 among MOFs. The storage capacity of C 2 H 2 is 234 cm 3 g −1 (298 K) and 330 cm 3 g −1 (273 K) at 1 atm for CPM‐733‐dps (the Co 2 V‐BDC form, BDC=1,4‐benzenedicarboxylate). These high uptake capacities are accomplished with low heat of adsorption, a feature desirable for low‐energy‐cost adsorbent regeneration. CPM‐733‐dps is stable and shows no loss of C 2 H 2 adsorption capacity following multiple adsorption–desorption cycles.

Wang, Yong↗
DOE OSTI2020

DNA Reaction–Diffusion Attractor Patterns

Abstract Living systems can form and recover complex chemical patterns with precisely sized features in the ranges of tens or hundreds of microns. We show how designed reaction–diffusion processes can likewise produce precise patterns, termed attractor patterns, that reform their precise shape after being perturbed. We use oligonucleotide reaction networks, photolithography, and microfluidic delivery to form precisely controlled attractor patterns and study the responses of these patterns to different localized perturbations. Linear and “hill”‐shaped patterns formed and stabilized into shapes and at time scales consistent with reaction–diffusion models. When patterns were perturbed in particular locations with UV light, they reliably reformed their steady‐state profiles. Recovery also occurred after repeated perturbations. By designing the far‐from‐equilibrium dynamics of a chemical system, this study shows how it is possible to design spatial patterns of molecules that are sustained and regenerated by continually evolving towards a specific steady state configuration.

Dorsey, Phillip James↗
DOE OSTI2020

Overcoming Fundamental Limitations in Adsorbent Design: Alkene Adsorption by Non‐porous Copper(I) Complexes

Abstract Purifying alkenes from alkanes requires cryogenic distillation. This consumes energy equivalent to countries of ca. 5 million people. Replacing distillation with adsorption processes would significantly increase energy efficiency. Trade‐offs between kinetics, selectivity, capacity, and heat of adsorption have prevented production of an optimal adsorbent. We report adsorbents that overcome these trade‐offs. [Cu‐Br] 3 and [Cu‐H] 3 are air‐stable trinuclear complexes that undergo reversible solid‐state inter‐molecular rearrangements to produce dinuclear [Cu‐Br⋅(alkene)] 2 and [Cu‐H⋅(alkene)] 2 . The reversible solid‐state rearrangement, confirmed in situ using powder X‐ray diffraction, allows adsorbent design trade‐offs to be overcome, coupling low heat of adsorption (−10 to −17 kJ mol −1 alkene ), high alkene:alkane selectivity (47; 29), and uptake capacity (>2.5 mol alkene mol −1 Cu3 ). Most remarkably, [Cu‐H] 3 displays fast uptake and regenerates capacity within 10 minutes.

Parasar, Devaborniny↗
DOE OSTI2021

Electrochemically Triggered Chain Reactions for the Conversion of Furan Derivatives

Abstract We report an electrochemical method for coupling biomass‐derived C5/C6 compounds to value‐added fuel precursors. Using only 2 % of equivalent charges, 2‐methylfuran (2‐MF) was oxidized to yield a cation radical, which readily reacted with 3‐hexene‐2,5‐dione, a derivate of 2,5‐dimethylfuran, to produce 3‐(5‐methylfuran‐2‐yl)hexane‐2,5‐dione. The product was converted to 4‐ethylnonane (a component of biodiesel/jet fuel) in a single step in excellent yield. Importantly, the reaction was not sensitive to oxygen, and a trace amount of water was found to promote the reaction. Detailed mechanistic studies confirmed the proposed reaction pathways. Key to the mechanism is the radical generation that is enabled by electrochemistry. The radical is regenerated at the end of a reaction cycle to ensure chain propagation for an average of ca. 47 times, resulting in an apparent Faradaic efficiency of 4700 %.

Chen, Rong↗
DOE OSTI2023

Spatiotemporal Control over Polynucleotide Brush Growth on DNA Origami Nanostructures

Abstract DNA nanotechnology provides an approach to create precise, tunable, and biocompatible nanostructures for biomedical applications. However, the stability of these structures is severely compromised in biological milieu due to their fast degradation by nucleases. Recently, we showed how enzymatic polymerization could be harnessed to grow polynucleotide brushes of tunable length and location on the surface of DNA origami nanostructures, which greatly enhances their nuclease stability. Here, we report on strategies that allow for both spatial and temporal control over polymerization through activatable initiation, cleavage, and regeneration of polynucleotide brushes using restriction enzymes. The ability to site‐specifically decorate DNA origami nanostructures with polynucleotide brushes in a spatiotemporally controlled way provides access to “smart” functionalized DNA architectures with potential applications in drug delivery and supramolecular assembly.

Yang, Yunqi↗
DOE OSTI2020

A Strategy for Constructing Pore-Space-Partitioned MOFs with High Uptake Capacity for C 2 Hydrocarbons and CO 2

Introduction of pore partition agents into hexagonal channels of MIL-88 type (acs topology) endows materials with high tunability in gas sorption. Here, we report a strategy to partition acs framework into pacs (partitioned acs) crystalline porous materials (CPM). This strategy is based on insertion of in situ synthesized 4, 4'-dipyridylsulfide (dps) ligands. As a result, one third of open metal sites in the parent acs net are retained in pacs MOFs, while two thirds are used for pore space partition. The newly synthesized Co 2 V-pacs MOFs, with optimized pore space and open metal sites, exhibit near or at record high uptake capacities for C 2 H 2 , C 2 H 4 , C 2 H 6 , and CO 2 among MOFs. For example, the storage capacity of C 2 H 2 is 234 cm 3 /g -1 (298 K) and 330 cm 3 /g -1 (273K) at 1 atm for CPM-733-dps (the Co 2 V-BDC form, BDC=1,4-benzenedicarboxylate), higher than benchmark MOFs such as MOF-74 and all other pacs members. These high uptake capacities are accomplished with low heat of adsorption, a feature desirable for low-energy-cost adsorbent regeneration. CPM-733-dps is stable and shows no loss of C 2 H 2 adsorption capacity following multiple adsorption–desorption cycles.

25 ENERGY STORAGE↗
DOE OSTI2020

DNA Reaction–Diffusion Attractor Patterns

Living systems can form and recover complex chemical patterns with precisely sized features in the ranges of tens or hundreds of microns. We show how designed reaction-diffusion processes can likewise produce precise patterns, termed attractor patterns, that reform their precise shape after being perturbed. We use oligonucleotide reaction networks, photolithography and microfluidic delivery to form precisely controlled attractor patterns and study the responses of these patterns to different localized perturbations. Linear and ‘hill’-shaped patterns formed and stabilized into shapes and at time scales consistent with reaction-diffusion models. When patterns were perturbed in particular locations with UV light, they reliably reformed their steady state profiles. Recovery also occurred after repeated perturbations. As a result, by designing the far-from-equilibrium dynamics of a chemical system, this study shows how it is possible to design spatial patterns of molecules that are sustained and regenerated by continually evolving towards a specific steady state configuration

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

Overcoming Fundamental Limitations in Adsorbent Design: Alkene Adsorption by Non-porous Copper(I) Complexes

Purifying alkenes from alkanes requires cryogenic distillation. This consumes energy equivalent to countries of ca. 5 million people. Replacing distillation with adsorption processes would significantly increase energy efficiency. Trade-offs between kinetics, selectivity, capacity, and heat of adsorption have prevented production of an optimal adsorbent. Here, we report adsorbents that overcome these trade-offs. [Cu-Br] 3 and [Cu-H] 3 are air-stable trinuclear complexes that undergo reversible solid-state inter-molecular rearrangements to produce dinuclear [Cu-Br∙(alkene)] 2 and [Cu-H∙(alkene)] 2 . The reversible solid-state rearrangement, confirmed in situ using powder X-ray diffraction, allows adsorbent design trade-offs to be overcome, coupling low heat of adsorption (-10 to -17 kJ mol -1 alkene ), high alkene:alkane selectivity (47; 29), and uptake capacity (>2.5 molalkene mol -1 Cu3 ). Most remarkably, [Cu-H] 3 displays fast uptake and regenerates capacity within 10 minutes.

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

Defying Thermodynamics: Stabilization of Alane Within Covalent Triazine Frameworks for Reversible Hydrogen Storage

Metastable metal hydrides such as AlH 3 have many attractive features as hydrogen storage media, but generally require complex reaction schemes for regeneration following H 2 release. Here in this paper, we demonstrate that the highly unfavorable thermodynamics of direct aluminum hydrogenation can be overcome by stabilizing alane within a nanoporous bipyridine-functionalized Covalent Triazine Framework (AlH 3 @CTF-bipyridine). This material and the counterpart AlH 3 @CTF-biphenyl rapidly desorb H 2 between 95 and 154 °C, with desorption complete at 250 °C. Sieverts measurements, 27 Al MAS NMR and 27 Al{ 1 H} REDOR experiments, and computational spectroscopy reveal that AlH 3 @CTF-bipyridine dehydrogenation is reversible at 60 °C under 700 bar hydrogen, >10 times lower pressure than that required to hydrogenate bulk aluminum. DFT calculations and EPR measurements support an unconventional mechanism whereby strong AlH 3 binding to bipyridine results in single-electron transfer to form AlH 2 (AlH 3 ) n clusters. The resulting size-dependent charge redistribution alters the dehydrogenation/rehydrogenation thermochemistry, suggesting a novel strategy to enable reversibility in high-capacity metal hydrides.

Coordination Chemistry↗
DOE OSTI2022

Zirconium Carbide Mediates Coke‐Resistant Methane Dry Reforming on Nickel‐Zirconium Catalysts

Abstract Graphitic deposits anti‐segregate into Ni 0 nanoparticles to provide restored CH 4 adsorption sites and near‐surface/dissolved C atoms, which migrate to the Ni 0 /ZrO 2 interface and induce local Zr x C y formation. The resulting oxygen‐deficient carbidic phase boundary sites assist in the kinetically enhanced CO 2 activation toward CO(g). This interface carbide mechanism allows for enhanced spillover of carbon to the ZrO 2 support, and represents an alternative catalyst regeneration pathway with respect to the reverse oxygen spillover on Ni‐CeZr x O y catalysts. It is therefore rather likely on supports with limited oxygen storage/exchange kinetics but significant carbothermal reducibility.

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

Spatiotemporal Control over Polynucleotide Brush Growth on DNA Origami Nanostructures

DNA nanotechnology provides an approach to create precise, tunable, and biocompatible nanostructures for biomedical applications. However, the stability of these structures is severely compromised in biological milieu due to their fast degradation by nucleases. Recently, we showed how enzymatic polymerization could be harnessed to grow polynucleotide brushes of tunable length and location on the surface of DNA origami nanostructures, which greatly enhances their nuclease stability. Here, in this study, we report on strategies that allow for both spatial and temporal control over polymerization through activatable initiation, cleavage, and regeneration of polynucleotide brushes using restriction enzymes. The ability to site‐specifically decorate DNA origami nanostructures with polynucleotide brushes in a spatiotemporally controlled way provides access to “smart” functionalized DNA architectures with potential applications in drug delivery and supramolecular assembly.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗