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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 829 records · Page 46
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

A General Route to Flame Aerosol Synthesis and In Situ Functionalization of Mesoporous Silica

Mesoporous silica is a versatile material for energy, environmental, and medical applications. In this work, for the first time, we report a flame aerosol synthesis method for a class of mesoporous silica with hollow structure and specific surface area exceeding 1000 m 2 /g -1 . We show its superior performance in water purification, drug carrier, and thermal insulation. Moreover, we propose a general route to produce mesoporous nanoshell supported nanocatalysts by in situ decorating active nanoclusters, including noble metal (Pt/SiO 2 ), transition metal (Ni/SiO 2 ), metal oxide (CrO 3 /SiO 2 ), and alumina support (Co/Al 2 O 3 ). As a prototypical application, we perform dry reforming of methane using Ni/SiO 2 , achieving constant 97% CH 4 and CO 2 conversions for more than 200 hours, dramatically outperforming MCM-41 supported Ni catalyst. This work provides a scalable strategy to produce mesoporous nanoshells and proposes an in situ functionalization mechanism to flexible catalysts design for many reactions.

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

Synthesis and Processing by Design of High-Nickel Cathode Materials

The high demand of lightweight, high energy density batteries for energy storage promotes new materials discovery and development. Despite the large number of battery materials being discovered, very few of them have been commercially deployed, mostly bottlenecked by synthesis and processing – namely, making certain phases with the desired structure and properties to meet the multifaceted performance requirements. Alternative to the traditional trial and error, we present here an in situ study aided synthesis- and processing-by-design approach. With specific examples, we illustrate how to use the approach to identify reaction pathways in synthesis and processing of high-Nickel (Ni) cathode materials for next-generation lithium-ion batteries, thereby ensuring precise control of their structure, morphology, and surface properties. Furthermore, perspectives are provided on the wide applicability of the approach to solving critical issues inherent to high-Ni cathodes and the new directions and opportunities in the area.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Water aging and the quality of organic carbon sources drive niche partitioning of the active bathypelagic prokaryotic microbiome

Abstract Due to the scarcity of organic matter (OM) sources in the bathypelagic (1000–4000 m depth), prokaryotic metabolism is believed to be concentrated on particles originating from the surface. However, the structure of active bathypelagic prokaryotic communities and how it changes across environmental gradients remains unexplored. Using a combination of 16S rRNA gene and transcripts sequencing, metagenomics, and substrate uptake potential measurements, here we aimed to explore how water masses aging and the quality of OM influence the structure of the active microbiome, and the potential implications for community function. We found that the relative contribution of taxa with a free‐living lifestyle to the active microbiome increased in older water masses that were enriched in recalcitrant OM, suggesting that these prokaryotes may also play a substantial role in the bathypelagic metabolism of vast areas of the ocean. In comparison to particle‐associated prokaryotes, free‐living prokaryotes exhibited lower potential metabolic rates, and harbored a limited number of two‐component sensory systems, suggesting they have less ability to sense and respond to environmental cues. In contrast, particle‐associated prokaryotes carried genes for particle colonization and carbohydrate utilization that were absent in prokaryotes with a free‐living lifestyle. Consistently, we observed that prokaryotic communities inhabiting older waters displayed reduced abilities to colonize particles, and higher capabilities to use complex carbon sources, compared to communities in waters with a higher proportion of labile OM. Our results provide evidence of regionalization of the bathypelagic active prokaryotic microbiome, unveiling a niche partitioning based on the quality of OM.

Marine & Freshwater Biology↗
DOE OSTI2020

Nanoscale Perspectives of Metal Degradation via In Situ Atom Probe Tomography

Abstract We report a unique in situ instrument development effort dedicated to studying gas/solid interactions relevant to heterogeneous catalysis and early stages of oxidation of materials via atom probe tomography and microscopy (APM). An in situ reactor cell, similar in concept to other reports, has been developed to expose nanoscale volumes of material to reactive gas environments, in which temperature, pressure, and gas chemistry are well controlled. We demonstrate that the combination of this reactor cell with APM techniques can aid in building a better mechanistic understanding of resultant composition and surface and subsurface structure changes accompanying gas/surface reactions in metal and metal alloy systems through a series of case studies: O 2 /Rh, O 2 /Co, and O 2 /Zircaloy-4. In addition, the basis of a novel operando mode of analysis within an atom probe instrument is also reported. The work presented here supports the implementation of APM techniques dedicated to atomic to near-atomically resolved gas/surface interaction studies of materials broadly relevant to heterogeneous catalysis and oxidation.

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

Understanding the adsorption and potential tear film stability properties of recombinant human lubricin and bovine submaxillary mucins in an in vitro tear film model

The wetting and adsorption properties for two glycoproteins, recombinant human lubricin and bovine submaxillary mucins (BSM) were evaluated on hydrophilic and hydrophobic glass dome surfaces in a simplified in vitro tear film model. Herein, we show that both recombinant human lubricin (rh-lubricin) and BSM solutions render surfaces hydrophilic and when the fluid films reach 500 nm or less, the fluids resist evaporation-driven breakup through a volumetric flux across the surface, which we believe is due to evaporation-driven solutocapillary flows. rh-Lubricin was able to maintain a wet film without spontaneous breakup for longer periods of time than BSM at lower concentrations, which we attribute to differences in adsorption properties, measured by QCM-D, that result from surface charge and structural differences (confirmed by zeta potential, DLS, and SAXS measurements).

60 APPLIED LIFE SCIENCES↗
DOE OSTI2026

Trends and limits of CO 2 capture in solid and liquid sorbents at standard conditions

Carbon capture and storage (CCS) plays a critical role in achieving climate change mitigation targets, offering a pathway to decarbonize power generation, industrial processes, and heat production while addressing atmospheric CO 2 removal. While CCS technologies are technically advanced, the widespread adoption of 100 % CO 2 capture capacities such as 1 mol of CO 2 /mol of material and 1 g CO 2 /g storage (targeted by the DARPA, Defense Sciences Office, USA Govt.) has raised questions about the feasibility of achieving higher capture capacities. In the context of limiting global warming to 1.5°C, reaching 100 % CO 2 capture capacity is increasingly necessary, with residual emissions requiring complementary carbon dioxide removal (CDR) technologies. This review exclusively focuses on the CO 2 capture capacities of various sorbents under standard conditions, using different evaluation metrics. This study explores the performance of solid and liquid sorbents under standard conditions, analyzing factors including surface area, pore structure, solvent type, and functionalization to identify materials optimized for industrial-scale CCS applications. Emerging sorbents, including ILs, MOFs, COFs, POPs, DES, RCC, hybrid materials, and reactive sorbents, offer significant potential for enhanced selectivity and energy-efficient regeneration. Through a systematic assessment of gravimetric, volumetric, and molar capacities, the study provides insights into material efficiencies and trade-offs, offering guidance on optimizing sorbent selection for specific applications. The research advances understanding of scalable CCS technologies, contributing to global efforts to achieve net-zero emissions and address the pressing challenge of climate change.

Absorption↗
DOE OSTI2022

Characteristics and radiolysis behavior of polyvinylchloride under accelerated proton and γ-irradiation

Here the effect of high energy protons and γ-irradiation on the structural properties, surface-energies, and toxicological properties of polyvinyl chloride (PVC) were studied due to the role PVC products play in many technologies including the nuclear industry. Accelerated 1–4 MeV protons impacting on PVC in vacuum lead to the formation of polyenyl radicals as shown by EPR and to an increase in free surface energy due to functionalization of the surface of the irradiated polymer. γ-irradiation leads to the formation of unsaturated bonds, carbonyl and hydroxyl groups as shown by IR and to the release of HCl. Correlated molecular orbital theory calculations of reaction thermodynamics were used to aid in the development of a mechanism in the absence of oxygen. The formation and accumulation of chromophores and auxochromic groups during γ-radiolysis of PVC leads to a gradual change of the initial white color of the polymer to yellow and then to brown and black with high sensitivity. A mixture of powdered PVC and silicate glue was used to determine the profile of a 60 Co γ-radiation beam on targets with a complex relief. γ-irradiated polymer does not have a local irritating effect due to a single application to the skin of mice in an adhesive mixture at a concentration of up to 5000 mg/kg. γ-radiolysis of PVC powder in air with a dose of up to 1400 kGy does not affect its acute toxicity when administered intragastrically to BDF1 mice. PVC and its γ-irradiated analogs are non-toxic at doses ≤5000 mg/kg.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2025

Investigation of electrode-electrolyte interfaces to enable non-flammable Li-ion batteries operating up to 125°C with liquid electrolyte

Non-flammable and high-temperature stable ionic liquid (IL)-based electrolytes could eliminate catastrophic battery failures and improve battery safety, but their poor electrochemical interaction with the LiNi x Mn y Co z O 2 (NMC) family of cathodes is a long-standing problem due to severe parasitic reactions at high temperature. Understanding surface and bulk structural mechanisms of NMC-type cathodes at elevated operational temperature is of paramount importance to facilitate stable electrochemical performance. Here, we report a non-flammable phosphonium IL-based cell chemistry that offers stable electrode-electrolyte interfaces, leading to electrochemical performance up to 125°C and high-temperature safety. We combine electrochemistry with multimodal X-ray spectroscopy methods to understand interfaces at elevated temperature (100°C). This nanoscale understating enables a proof-of-concept high-temperature cylindrical cell (14500), and the design achieves an average Coulombic efficiency of ≈99.5% up to 300 cycles at 100°C. The results ascertain the significance of depth-dependent degradation at the interface, guiding room-temperature Li-ion technology toward extreme-temperature applications.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Plasma sheath and presheath development near a partially reflective surface

This work addresses one-dimensional evolution of a collisionless plasma next to a solid surface that is immersed into the plasma instantaneously. In particular, we consider how the self-similar rarefaction wave establishes dynamically and how the electron reflection from the surface modifies the structure of the rarefaction wave and the Debye sheath. Here, we demonstrate that a sufficiently strong reflection eliminates the Debye sheath and changes the wall potential and the plasma flow parameters significantly. The paper presents numerical results that illustrate the developed analytical theory.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2021

Deep Learning Segmentation of Complex Features in Atomic-Resolution Phase-Contrast Transmission Electron Microscopy Images

Phase-contrast transmission electron microscopy (TEM) is a powerful tool for imaging the local atomic structure of materials. TEM has been used heavily in studies of defect structures of two-dimensional materials such as monolayer graphene due to its high dose efficiency. However, phase-contrast imaging can produce complex nonlinear contrast, even for weakly scattering samples. It is, therefore, difficult to develop fully automated analysis routines for phase-contrast TEM studies using conventional image processing tools. For automated analysis of large sample regions of graphene, one of the key problems is segmentation between the structure of interest and unwanted structures such as surface contaminant layers. In this study, we compare the performance of a conventional Bragg filtering method with a deep learning routine based on the U-Net architecture. We show that the deep learning method is more general, simpler to apply in practice, and produces more accurate and robust results than the conventional algorithm. We provide easily adaptable source code for all results in this paper and discuss potential applications for deep learning in fully automated TEM image analysis.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

Multifunctional two-dimensional metal-organic frameworks for radionuclide sequestration and detection

Two lanthanide containing porous coordination polymers, [Ln2(bpdc)6(phen)2] · nH2O (1) and [Ln2(bpdc)6(terpy)2] · 3H2O (2) (Ln = either Pr, Nd or Sm-Dy); bpdc: 2,2'-bipyridine-5,5'-dicarboxylic acid, phen: 1,10-phenanthroline, and terpy: 2,2':6',2''-terpyridine, have been hydrothermally synthesized and structurally characterized by powder and single crystal X-ray diffraction. The crystallographic analyses reveal compounds 1 and 2 feature Ln3+ containing dimeric nodes that form a porous two-dimensional (2D) and non-porous three-dimensional (3D) framework, respectively. Each material is stable in aqueous media between pH 3-10 and exhibits modest thermal stability to ~400ºC. Notably, a portion of the phen and bpdc ligands in 1 can be removed thermally, without compromising the crystal structure, causing the surface area and pore volume to increase. The optical properties of 1 and 2 with Gd3+, Sm3+, Tb3+, and Eu3+ were explored in the solid-state using absorbance, fluorescence, and lifetime spectroscopies. The analyses reveal a complex blend of metal and ligand emission in the materials containing Sm3+ and Tb3+, while those featuring Eu3+ are dominated by intense metal-based emission. Compound 1 with Eu3+ displayed promise for the capture and detection of the uranyl cation, (UO2)2+, from aqueous media. In short, uranyl capture was observed at pH 4 and the adsorption thereof was detectable via vibrational and fluorescence spectroscopies and colorimetrically as the off-white color of 1 turned yellow with uptake. Finally, both 1 and 2 with Eu3+ produce bright red emission upon irradiation with Cu ka X-ray radiation (8.04 keV) and are candidate materials for applications in solid-state scintillation.

Surbella, Robert G.↗
DOE OSTI2023

The Chemical and Electronic Properties of Stability-Enhanced, Mixed Ir-TiO x Oxygen Evolution Reaction Catalysts

Iridium has emerged as the leading catalyst material for the anodic oxygen evolution reaction (OER) in acidic media. Often, iridium is mixed with more stable materials such as titanium. For these materials, the electronic structure of titanium plays a crucial role since with varying degrees of oxidation titanium transforms to semiconducting or even insulating phases. Yet, the electronic properties of mixed Ir-TiO x catalysts have never been systematically studied. In this study, we correlate the catalytic performance of mixed Ir-TiO x -based OER catalysts with the electronic structure of the surface layers. For this, a thin film material library with a 20-70 at. % Ir (Ir/[Ir + Ti]) compositional gradient was prepared. We used inductively coupled plasma mass spectrometry to test the OER activity and stability of the set of mixed Ir-TiO x catalyst candidate materials. Complementary, Ti L 2,3 - and O K-edge X-ray absorption spectroscopy and depth-dependent X-ray photoelectron spectroscopy measurements were performed to correlate the catalytic performance with the composition and electronic property profiles of these mixed Ir-TiO x OER anode catalysts. The spectroscopic analysis reveals that titanium is present as an intermixed matrix of semiconductive but stable TiO 2 , conductive but less stable titanium-suboxides (TiO x ), and highly conductive but highly unstable metallic Ti(0). The extent of the titanium oxidation strongly depends on the titanium content, with a lower degree of oxidation observed for lower titanium (and thus higher iridium) contents. For an iridium loading of 70 at. %, the respective mixed Ir-TiO x catalyst showed a similar OER activity to that of the pure metallic iridium (1.74 vs 1.59 VRHE, respectively) but with a 71% lower iridium dissolution rate relative to the pure metallic iridium. This demonstrates the stabilization effect of titanium addition while maintaining high OER activity.

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

Efficient Lithium Metal Cycling over a Wide Range of Pressures from an Anion-Derived Solid-Electrolyte Interphase Framework

Advanced electrolytes were developed to improve the cyclability of lithium (Li) metal anodes, yet their working mechanisms remain unclear. Here, we study the Li cycling performance under different pressures in a 1 M Li bis(fluorosulfonyl)imide/fluorinated 1,4-dimethoxybutane electrolyte. A consistently long cycle life is achieved over a wide range of pressures (30–600 psi). We find that this is due to a completely different Li plating mode with more favorable deposition morphologies compared to that in a conventional carbonate electrolyte, which exhibits increasing cycle stability with increased pressure. We show that this is enabled by the properties of an anion-derived residual solid-electrolyte interphase (rSEI) framework on the electrode surface, an undercharacterized structure with profound implications for Li metal cycling. This anion-derived rSEI chemistry is likely the key to a prolonged cycle life of Li metal batteries and should be vigorously addressed in future electrolyte designs.

25 ENERGY STORAGE↗
DOE OSTI2024

Deciphering Chemical/Electrochemical Compatibility of Li 3 InCl 6 in 5.2 V High-Voltage LiCoO 2 All-Solid-State Batteries

Large interfacial resistance is a widely recognized impediment to the advancement of high-voltage, all-solid-state batteries. However, a comprehensive understanding of the fundamental cause behind the interfacial resistance between solid electrolytes and typical layered oxide cathodes has not yet been achieved. Here, we investigated the high-voltage stability of Li 3 InCl 6 and elucidated the underlying interfacial electrochemical reactions between LiCoO 2 and Li 3 InCl 6 . Further, the pairing of Li 3 InCl 6 with LiCoO 2 exhibited a superior capacity retention of 73.6% even at 5.2 V, much higher than 28.2% charged at 4.6 V in lithium-ion batteries after 70 cycles. The enhanced high-voltage stability of ASSBs is attributed to the stable interface formed between LiCoO 2 and Li 3 InCl 6 and the reinforced surface and bulk structure stability. On the other hand, the ultrahigh voltage still causes the partial decomposition of Li 3 InCl 6 and generates interfacial compounds such as InClO and cobalt and indium chlorides/oxides.

25 ENERGY STORAGE↗