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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 919 records · Page 51
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Simultaneous Control of Pore‐Space Partition and Charge Distribution in Multi‐Modular Metal–Organic Frameworks

Abstract We report here a strategy for making anionic pacs type porous materials by combining pore space partition with charge reallocation. The method uses the first negatively charged pore partition ligand (2,5,8‐tri‐(4‐pyridyl)‐1,3,4,6,7,9‐hexaazaphenalene, H‐tph) that simultaneously enables pore partition and charge reallocation. Over two dozen anionic pacs materials have been made to demonstrate their excellent chemical stability and a high degree of tunability. Notably, Ni 3 ‐bdt‐tph (bdt=1,4‐benzeneditetrazolate) exhibits month‐long water stability, while CoV‐bdt‐tph sets a new benchmark for C 2 H 2 storage capacity under ambient conditions for ionic MOFs. In addition to tunable in‐framework modules, we show feasibility to tune the type and concentration of extra‐framework counter cations and their influence on both stability and capability to separate industrial C 3 H 8 /C 3 H 6 and C 6 H 6 /C 6 H 12 mixtures.

Hong, Anh N.↗
DOE OSTI2022

Highly Efficient Organosulfur and Lithium‐Metal Hosts Enabled by C@Fe 3 N Sponge

Abstract Lithium‐organosulfur (Li‐OS) batteries, despite possessing high theoretical specific capacity, encounter a few practical challenges, including unsatisfactory lifespan and low active material utilization under realistic conditions. Here, diisoropyl xanthogen polysulfide (DIXPS) has been selected as a model organosulfur compound to investigate the practical feasibility of Li‐OS batteries under realistic conditions. A well‐designed freestanding carbon sponge decorated with Fe 3 N nanoparticles (C@Fe 3 N) is introduced into the Li‐OS cells as a scaffold for both Li and DIXPS. The lithiophilic property of the C@Fe 3 N host guides uniform lithium deposition at the anode, and the catalysis of the DIXPS conversion reaction promotes the kinetics at the cathode. Impressively, the synergistic effect of C@Fe 3 N leads to an extremely stable cycling performance over 1 000 cycles in a Li‐OS full cell under realistic conditions.

He, Jiarui↗
DOE OSTI2023

Photochemically‐Driven CO 2 Release Using a Metastable‐State Photoacid for Energy Efficient Direct Air Capture

Abstract One of the grand challenges underlying current direct air capture (DAC) technologies relates to the intensive energy cost for sorbent regeneration and CO 2 release, making the massive scale (GtCO 2 /year) deployment required to have a positive impact on climate change economically unfeasible. This challenge underscores the critical need to develop new DAC processes with substantially reduced regeneration energies. Here, we report a photochemically‐driven approach for CO 2 release by exploiting the unique properties of an indazole metastable‐state photoacid (mPAH). Our measurements on simulated and amino acid‐based DAC systems revealed the potential of mPAH to be used for CO 2 release cycles by regulating pH changes and associated isomers driven by light. Upon irradiating with moderate intensity light, a ≈55 % and ≈68 % to ≈78 % conversion of total inorganic carbon to CO 2 was found for the simulated and amino acid‐based DAC systems, respectively. Our results confirm the feasibility of on‐demand CO 2 release under ambient conditions using light instead of heat, thereby providing an energy efficient pathway for the regeneration of DAC sorbents.

Premadasa, Uvinduni I.↗
DOE OSTI2025

A Universal Design of Lithium Anode via Dynamic Stability Strategy for Practical All‐Solid‐State Batteries

Abstract All‐solid‐state Li‐metal battery (ASSLB) chemistry with thin solid‐state electrolyte (SSE) membranes features high energy density and intrinsic safety but suffers from severe dendrite formation and poor interface contact during cycling, which hampers the practical application of rechargeable ASSLB. Here, we propose a universal design of thin Li‐metal anode (LMA) via a dynamic stability strategy to address these issues. The ultra‐thin LMA (20 μm) is in situ constructed with uniform highly Li‐ion conductive solid‐electrolyte interphase and composite‐polymer interphase (CPI) via electroplating process. As a result, the passivation layer with poor Li‐ion conduction on Li anode can be dissolved and small surface resistance can be achieved due to the good compatibility of CPI to SSEs. The cycling of Li symmetric cell with Li 6 PS 5 Cl thin film electrolyte (<100 μm) shows a high critical current density of >2.0 mA cm −2 with excellent cycling stability at 1.0 mA cm −2 . The ASSLBs paring with Ni‐rich LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathode demonstrated the feasibility of engineered LMA design by presenting good rate capability from 0.1 C to 1.0 C at room temperature, as well as long‐term cycling stability (81 % retention after 100 cycles). This work represents a general pathway to make thin dendrite‐free LMA available for high‐energy‐density ASSLBs.

Deng, Tao [Department of Chemical and Biomolecular↗
DOE OSTI2025

Towards the Stable Chelation of Radioantimony(V) for Targeted Auger Theranostics

Abstract Antimony‐119 ( 119 Sb) is one of the most attractive Auger‐electron emitters identified to date, but it remains practically unexplored for targeted radiotherapy because no chelators have been identified to stably bind this metalloid in vivo. In a departure from current studies focused on chelator development for Sb(III), we explore the chelation chemistry of Sb(V) using the tris‐catecholate ligand TREN‐CAM. Through a combination of radiolabeling, spectroscopic, solid‐state, and computational studies, the radiochemistry and structural chemistry of TREN‐CAM with 1XX/nat Sb(V) were established. The resulting [ 1XX Sb]Sb–TREN‐CAM complex remained intact for several days in human serum, signifying high stability under biological conditions. Finally, the first in vivo single photon emission computed tomography and positron emission tomography imaging studies were carried out using 117 Sb, the diagnostic analogue of 119 Sb. These studies revealed marked differences in the uptake and distribution of activity in mice administered unchelated [ 117 Sb]Sb(OH) 6 – versus [ 117 Sb]Sb–TREN‐CAM, suggesting that 117 Sb is largely retained by TREN‐CAM over the time course of the study. Collectively, these findings demonstrate the most physiologically stable complex of no‐carrier‐added 1XX Sb yet reported, offering new promise for the clinical implementation of radioantimony in nuclear medicine. Our results also establish the feasibility of 117 Sb as an elementally matched partner to 119 Sb for theranostic applications.

Olson, Aeli P. [Department of Medical Physics Univ↗
DOE OSTI2025

Explainable Synthesizability Prediction of Inorganic Crystal Polymorphs Using Large Language Models

Abstract We evaluate the ability of machine learning to predict whether a hypothetical crystal structure can be synthesized and explain those predictions to scientists. Fine‐tuned large language models (LLMs) trained on a human‐readable text description of the target crystal structure perform comparably to previous bespoke convolutional graph neural network methods, but better prediction quality can be achieved by training a positive‐unlabeled learning model on a text‐embedding representation of the structure. An LLM‐based workflow can then be used to generate human‐readable explanations for the types of factors governing synthesizability, extract the underlying physical rules, and assess the veracity of those rules. These explanations can guide chemists in modifying or optimizing non‐synthesizable hypothetical structures to make them more feasible for materials design.

Kim, Seongmin [Department of Chemical and Biologic↗
DOE OSTI2021

Boosting CO 2 Electrochemical Reduction with Atomically Precise Surface Modification on Gold Nanoclusters

Thiolate-protected gold nanoclusters (NCs) are promising catalytic materials for the electrochemical CO 2 reduction reaction (CO 2 RR). In this work an atomic level modification of a Au 23 NC is made by substituting two surface Au atoms with two Cd atoms, and it enhances the CO 2 RR selectivity to 90–95 % at the applied potential between -0.5 to -0.9 V, which is doubled compared to that of the undoped Au 23 . Additionally, the Cd-doped Au 19 Cd 2 exhibits the highest CO 2 RR activity (2200 mA mg -1 at -1.0 V vs. RHE) among the reported NCs. This synergetic effect between Au and Cd is remarkable. Density-functional theory calculations reveal that the exposure of a sulfur active site upon partial ligand removal provides an energetically feasible CO 2 RR pathway. The thermodynamic energy barrier for CO formation is 0.74 eV lower on Au 19 Cd 2 than on Au 23 . Here these results reveal that Cd doping can boost the CO 2 RR performance of Au NCs by modifying the surface geometry and electronic structure, which further changes the intermediate binding energy. This work offers insights into the surface doping mechanism of the CO 2 RR and bimetallic synergism.

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

Simultaneous Control of Pore-Space Partition and Charge Distribution in Multi-Modular Metal–Organic Frameworks

Here we report here a strategy for making anionic pacs type porous materials by combining pore space partition with charge reallocation. The method uses the first negatively charged pore partition ligand (2,5,8-tri-(4-pyridyl)-1,3,4,6,7,9-hexaazaphenalene, H-tph) that simultaneously enables pore partition and charge reallocation. Over two dozen anionic pacs materials have been made to demonstrate their excellent chemical stability and a high degree of tunability. Notably, Ni 3 -bdt-tph (bdt=1,4-benzeneditetrazolate) exhibits month-long water stability, while CoV-bdt-tph sets a new benchmark for C 2 H 2 storage capacity under ambient conditions for ionic MOFs. In addition to tunable in-framework modules, we show feasibility to tune the type and concentration of extra-framework counter cations and their influence on both stability and capability to separate industrial C 3 H 8 /C 3 H 6 and C 6 H 6 /C 6 H 12 mixtures.

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

Highly Efficient Organosulfur and Lithium-Metal Hosts Enabled by C@Fe 3 N Sponge

Lithium-organosulfur (Li-OS) batteries, despite possessing high theoretical specific capacity, encounter a few practical challenges, including unsatisfactory lifespan and low active material utilization under realistic conditions. Here, diisoropyl xanthogen polysulfide (DIXPS) has been selected as a model organosulfur compound to investigate the practical feasibility of Li-OS batteries under realistic conditions. A well-designed freestanding carbon sponge decorated with Fe 3 N nanoparticles (C@Fe 3 N) is introduced into the Li-OS cells as a scaffold for both Li and DIXPS. The lithiophilic property of the C@Fe 3 N host guides uniform lithium deposition at the anode, and the catalysis of the DIXPS conversion reaction promotes the kinetics at the cathode. Impressively, the synergistic effect of C@Fe 3 N leads to an extremely stable cycling performance over 1000 cycles in a Li-OS full cell under realistic conditions.

25 ENERGY STORAGE↗
DOE OSTI2023

Photochemically-Driven CO 2 Release Using a Metastable-State Photoacid for Energy Efficient Direct Air Capture

One of the grand challenges underlying current direct air capture (DAC) technologies relates to the intensive energy cost for sorbent regeneration and CO 2 release, making the massive scale (GtCO 2 /year) deployment required to have a positive impact on climate change economically unfeasible. This challenge underscores the critical need to develop new DAC processes with substantially reduced regeneration energies. Here, in this work, we report a photochemically-driven approach for CO 2 release by exploiting the unique properties of an indazole metastable-state photoacid (mPAH). Our measurements on simulated and amino acid-based DAC systems revealed the potential of mPAH to be used for CO 2 release cycles by regulating pH changes and associated isomers driven by light. Upon irradiating with moderate intensity light, a ≈55 % and ≈68 % to ≈78 % conversion of total inorganic carbon to CO 2 was found for the simulated and amino acid-based DAC systems, respectively. Our results confirm the feasibility of on-demand CO 2 release under ambient conditions using light instead of heat, thereby providing an energy efficient pathway for the regeneration of DAC sorbents.

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

Facile, Versatile and Stepwise Synthesis of High‐Performance Oligomer Acceptors for Stable Organic Solar Cells

Abstract Oligomer acceptors have recently emerged as promising photovoltaic materials for achieving high power conversion efficiency (PCE) and long‐term stability in organic solar cells (OSCs). However, the limited availability of diverse acceptors, resulting from the sole synthetic approach, has hindered their potential for future industrialization. In this study, we present a facile and effective stepwise approach that utilizes two consecutive Stille coupling reactions for the synthesis of oligomer acceptors. To demonstrate the feasibility of the novel approach, we successfully synthesize a trimer acceptor, Tri‐Y6‐OD, and further systematically investigate the impact of oligomerization on device performance and stability. The results reveal that this approach has significant advantages compared to the conventional method, including reduced formation of unwanted by‐products and lower difficulties in purification. Remarkably, the OSC based on PM6 : Tri‐Y6‐OD achieves an impressive PCE of 18.03 % and maintains 80 % of the initial PCE (T 80 ) for 1523 h under illumination, surpassing the performance of the corresponding small molecule acceptor Y6‐OD‐based device. Furthermore, the versatility of the synthetic strategy in obtaining diverse acceptors is further demonstrated. Overall, our findings provide a facile, versatile and stepwise way for synthesizing oligomer acceptors, thereby facilitating the development of stable and efficient OSCs.

Chemistry↗
DOE OSTI2023

A GPT‐4 Reticular Chemist for Guiding MOF Discovery**

Abstract We present a new framework integrating the AI model GPT‐4 into the iterative process of reticular chemistry experimentation, leveraging a cooperative workflow of interaction between AI and a human researcher. This GPT‐4 Reticular Chemist is an integrated system composed of three phases. Each of these utilizes GPT‐4 in various capacities, wherein GPT‐4 provides detailed instructions for chemical experimentation and the human provides feedback on the experimental outcomes, including both success and failures, for the in‐context learning of AI in the next iteration. This iterative human‐AI interaction enabled GPT‐4 to learn from the outcomes, much like an experienced chemist, by a prompt‐learning strategy. Importantly, the system is based on natural language for both development and operation, eliminating the need for coding skills, and thus, make it accessible to all chemists. Our collaboration with GPT‐4 Reticular Chemist guided the discovery of an isoreticular series of MOFs, with each synthesis fine‐tuned through iterative feedback and expert suggestions. This workflow presents a potential for broader applications in scientific research by harnessing the capability of large language models like GPT‐4 to enhance the feasibility and efficiency of research activities.

Chemistry↗
DOE OSTI2024

Rewritable Surface‐Grafted Polymer Brushes with Dynamic Covalent Linkages

Abstract Surface grafting of polymer brushes drastically modifies surface properties, including wettability, compatibility, responsiveness, etc. A broad variety of functionalities can be introduced to the surface via different types of polymers. Bringing together properties of two or more types of polymer brushes to one surface opens up even more possibilities in brush‐modified materials. However, while it is generally feasible to introduce several chemical compositions along the brushes via copolymerization, it is challenging to vary the types of polymer brushes along a surface. Although previous studies have demonstrated binary brushes via orthogonal polymerization techniques or partial deactivation/regrafting, they commonly limit the number of polymer types to two. Here, we propose a strategy to introduce dynamic covalent diketoenamine linkages at the root of polymer brushes. The grafting density could be precisely tuned during surface functionalization. The surface‐anchored polymer brushes were cleaved by the addition of small molecule amines. New polymer brushes can be regrafted from the surface following refunctionalization of exposed sites. The maneuverability allows tuning of the types and densities of the polymer brushes, pointing the way to the preparation of a new generation of well‐defined brush‐modified materials with mixed grafts, with potential applications in the design of smart materials and surfaces.

Cui, Feichen↗
DOE OSTI2025

A Universal Design of Lithium Anode via Dynamic Stability Strategy for Practical All‐Solid‐State Batteries

Abstract All‐solid‐state Li‐metal battery (ASSLB) chemistry with thin solid‐state electrolyte (SSE) membranes features high energy density and intrinsic safety but suffers from severe dendrite formation and poor interface contact during cycling, which hampers the practical application of rechargeable ASSLB. Here, we propose a universal design of thin Li‐metal anode (LMA) via a dynamic stability strategy to address these issues. The ultra‐thin LMA (20 μm) is in situ constructed with uniform highly Li‐ion conductive solid‐electrolyte interphase and composite‐polymer interphase (CPI) via electroplating process. As a result, the passivation layer with poor Li‐ion conduction on Li anode can be dissolved and small surface resistance can be achieved due to the good compatibility of CPI to SSEs. The cycling of Li symmetric cell with Li 6 PS 5 Cl thin film electrolyte (<100 μm) shows a high critical current density of >2.0 mA cm −2 with excellent cycling stability at 1.0 mA cm −2 . The ASSLBs paring with Ni‐rich LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathode demonstrated the feasibility of engineered LMA design by presenting good rate capability from 0.1 C to 1.0 C at room temperature, as well as long‐term cycling stability (81 % retention after 100 cycles). This work represents a general pathway to make thin dendrite‐free LMA available for high‐energy‐density ASSLBs.

Deng, Tao [Department of Chemical and Biomolecular↗
DOE OSTI2025

Towards the Stable Chelation of Radioantimony(V) for Targeted Auger Theranostics

Antimony-119 ( 119 Sb) is one of the most attractive Auger-electron emitters identified to date, but it remains practically unexplored for targeted radiotherapy because no chelators have been identified to stably bind this metalloid in vivo. In a departure from current studies focused on chelator development for Sb(III), we explore the chelation chemistry of Sb(V) using the tris-catecholate ligand TREN-CAM. Through a combination of radiolabeling, spectroscopic, solid-state, and computational studies, the radiochemistry and structural chemistry of TREN-CAM with 1XX/nat Sb(V) were established. The resulting [ 1XX Sb]Sb–TREN-CAM complex remained intact for several days in human serum, signifying high stability under biological conditions. Finally, the first in vivo single photon emission computed tomography and positron emission tomography imaging studies were carried out using 117 Sb, the diagnostic analogue of 119 Sb. These studies revealed marked differences in the uptake and distribution of activity in mice administered unchelated [ 117 Sb]Sb(OH) 6 – versus [ 117 Sb]Sb–TREN-CAM, suggesting that 117 Sb is largely retained by TREN-CAM over the time course of the study. Collectively, these findings demonstrate the most physiologically stable complex of no-carrier-added 1XX Sb yet reported, offering new promise for the clinical implementation of radioantimony in nuclear medicine. In conclusion, our results also establish the feasibility of 117 Sb as an elementally matched partner to 119 Sb for theranostic applications.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2025

Explainable Synthesizability Prediction of Inorganic Crystal Polymorphs Using Large Language Models

Abstract We evaluate the ability of machine learning to predict whether a hypothetical crystal structure can be synthesized and explain those predictions to scientists. Fine‐tuned large language models (LLMs) trained on a human‐readable text description of the target crystal structure perform comparably to previous bespoke convolutional graph neural network methods, but better prediction quality can be achieved by training a positive‐unlabeled learning model on a text‐embedding representation of the structure. An LLM‐based workflow can then be used to generate human‐readable explanations for the types of factors governing synthesizability, extract the underlying physical rules, and assess the veracity of those rules. These explanations can guide chemists in modifying or optimizing non‐synthesizable hypothetical structures to make them more feasible for materials design.

Kim, Seongmin [Department of Chemical and Biologic↗
DOE OSTI2025

Mono‐Materials Created by Engineering a Continuum of P3HB Stereomicrostructures in a One‐Step Catalytic Process

Multi-material products that combine multiple complementary polymers can create products with desired performance but present challenges to end-of-life (EoL) management. The emerging mono-material product design based on a single polymer type addresses the fundamental EoL issue, but challenges of delivering vastly tunable material properties by the single polymer still remain. Here, we introduce a simple strategy to produce biodegradable poly(3-hydroxybutyrate) (P3HB) materials with a wide range of material properties by engineering a stereomicrostructure continuum, achieved through polymerizing diastereomeric mixtures of racemic and meso-dimethyl diolides at various feed ratios with a single catalyst. This one-step, one-pot process produces biodegradable P3HB mono-materials ranging from rigid to flexible thermoplastics, to tough thermoplastic elastomers, to a pressure-sensitive adhesive (PSA), which have been then combined to fabricate prototype all-P3HB PSA tapes, demonstrating the feasibility of designing mono-material products through engineering polymer stereomicrostructures.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Two Artificial Leaf Architectures for Solar Formate Production From CO 2 and H 2 O

Sunlight-powered artificial leaves for the production of formate from CO 2 are an attractive route to solar fuels, yet existing solar formate devices remain low in performance, and their architecture and material choices are underexplored. Herein, we report the fabrication of two distinct fully integrated, self-standing solar formate device architectures and elucidate the underlying design principles and material selection strategies. The first architecture integrates a Si photocathode with a BiVO 4 photoanode and utilizes a highly active Pd catalyst for CO 2 reduction. It represents the first artificial leaf device comprising two photoelectrodes (excluding photovoltaic [PV]-biased electrodes) for effective formate production under single-beam illumination. The second architecture employs a dark cathode and a dark anode driven by a 4-junction perovskite solar cell and uses a highly stable Bi catalyst for CO 2 reduction. This device delivers a record-high formate production rate of 174 µmol h −1 with a remarkable solar-to-formate energy efficiency of 2% among all artificial leaf devices reported to date. Finally, these results demonstrate the feasibility and outline the design principles of both PV-free and PV-assisted device architectures in solar fuel production.

electrocatalysis↗