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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 1,621 records · Page 90
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Cu-, Co-, and Zn-Based Metal–Organic Framework-Derived Nanoporous Ion Emitters for Picogram Level Analysis of Actinides

Thermal ionization mass spectrometry (TIMS) is often regarded as the preferred technique for trace-level isotopic analysis of actinides owing to its high sensitivity and absence of carry-over effects. However, actinide sample utilization efficiency (SUE) is typically low (<0.05%) without the use of activators or specialized loading approaches which can yield SUEs of >5%. To this effect, we investigate a series of metal–organic framework (MOF)-based nanoporous ion emitters (nano-PIEs) that show enhanced ionization of actinides when used in TIMS loading. We study the impact of physical and chemical properties of MOFs on TIMS SUEs using two families of MOFs that can be synthesized under similar reaction conditions. The structural and chemical properties of these MOFs can be systematically modified one at a time while keeping other features the same. This allows us to strategically investigate their impact on SUEs. The first family of MOFs considered in this study is Zeolitic Imidazole Frameworks (ZIFs) which are made using 2 methyl-imidazole as an organic linker with zinc (ZIF-8) and cobalt (ZIF-67) as metal centers. Additionally, the effect of morphology was also studied using Zn-based ZIF-L with a 2-dimensional structure. The second family of MOFs was synthesized using benzene-1,3,5-tricarboxylate (BTC) with copper (Cu-BTC) and zinc (Zn-BTC) as the metal center. Among the MOFs tested, Cu-BTC showed the highest SUE with an average SUE of 0.27 ± 0.15%, followed closely by Zn-BTC (0.24 ± 0.10%), ZIF-8 (0.17 ± 0.10%), and trailed by the other MOFs. When the MOFs were pyrolyzed in N 2 before loading, an apparent increase in the SUE was observed with ZIF-8 and Cu-BTC showing average SUEs of 0.25 ± 0.08% and 0.34 ± 0.13%, respectively, with the highest measured SUE of 0.53% for pyrolyzed Cu-BTC. In conclusion, this observed increase in SUE by up to an order of magnitude compared to bare filaments demonstrates the efficacy and potential of MOF-derived nano-PIEs for TIMS application.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Water-Soluble 3D Covalent Organic Framework that Displays an Enhanced Enrichment Effect of Photosensitizers and Catalysts for the Reduction of Protons to H 2

Covalent organic frameworks (COFs) are emerging porous polymers that have 2D or 3D long-range ordering. Currently available COFs are typically insoluble or decompose upon dissolution, which remarkably restricts their practical implementations. For 3D COFs, the achievement of noninterpenetration, which maximizes their porosity-derived applications, also remains a challenge synthetically. Here, we report the synthesis of the first highly water-soluble 3D COF (sCOF-101) from irreversible polymerization of a preorganized supramolecular organic framework through cucurbit[8]uril (CB[8])-controlled [2 + 2] photodimerization. Synchrotron X-ray scattering and diffraction analyses confirm that sCOF-101 exhibits porosity periodicity, with a channel diameter of 2.3 nm, in both water and the solid state and retains the periodicity under both strongly acidic and basic conditions. As an ordered 3D polymer, sCOF-101 can enrich [Ru(bpy) 3 ] 2+ photosensitizers and redox-active polyoxometalates in water, which leads to remarkable increase of their photocatalytic activity for proton reduction to produce H2.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Applying the Risk Management Framework: The Distributed Energy Resource Risk Manager

As part of a multiyear effort, the National Renewable Energy Laboratory (NREL) has dedicated resources to understand and identify cybersecurity weaknesses in distributed energy resources (DERs) by performing assessments. Due to a lack of standardization and rapidly increasing adoption of DERs, there is a critical need to address cybersecurity needs for DER systems in an interactive way. Furthermore, federal agencies, which are required to obtain an authority to operate, are challenged by the complexities of including their DERs. To help meet this need, in early 2020, NREL released the Distributed Energy Resources Cybersecurity Framework (DERCF) and accompanying Web application. This process is supported by the Risk Management Framework (RMF) developed by the National Institute of Standards and Technology. This project, referred to as the DERCF RMF application, expands on the existing DERCF work to include methods that support walking a user through the seven RMF steps. The tool will be available for download at no cost from [link ]. The purpose of this paper is to describe the steps the DERCF team at NREL took to understand Steps 1-5 of the RMF process. Additionally, this document will identify future work on the first five steps as well as a plan for Steps 6 and 7.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2023

Generalized Bayesian Framework for Evaluation of Integral Benchmark Experiments [Slides]

This presentation is on generalized Bayesian framework for evaluation of integral benchmark experiments. This presentation starts off with assumptions and approximations used with Bayes Theorem. then an overview of approximations used by ORNL codes, and Generalized Bayesian Monto Carlo (GBMC). The presentation then details out a precise framework. This presentation then concludes with considerations.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2023

Cybersecurity Framework Profile for Electric Vehicle Extreme Fast Charging Infrastructure

This document is the Cybersecurity Framework Profile (Profile) developed for the Electric Vehicle Extreme Fast Charging (EV/XFC) ecosystem, including the four domains that relies on the ecosystem (i) Electric Vehicles (EV); (ii) Extreme Fast Charging (XFC); (iii) XFC Cloud or Third-Party Operations; and (iv) Utility and Building Networks. This Profile utilizes the NIST Cybersecurity Framework Version 1.1 and provides voluntary guidance to help relevant parties develop Profiles specific to their organization to understand, assess, and communicate their cybersecurity posture as a part of their risk management process. The Profile is intended to supplement, not replace, an existing risk management program or cybersecurity standards, regulations, and industry guidelines that are in current use by the EV/XFC industry.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2014

Peptide assembly-driven metal-organic framework (MOF) motors for micro electric generators

Peptide–metal–organic framework (Pep-MOF) motors, whose motions are driven by anisotropic surface tension gradients created via peptide self-assembly around frameworks, can rotate microscopic rotors and magnets fast enough to generate an electric power of 0.1 μW. Finally, a new rigid Pep-MOF motor can be recycled by refilling the peptide fuel into the nanopores of the MOF.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Symmetry is the Key to the Design of Reticular Frameworks

De novo prediction of reticular framework structures is a challenging task for chemists and materials scientists. Herein, a computational workflow that predicts a list of possible reticular frameworks based on only the connectivity and symmetry of node and linker building blocks is presented. This list is ranked based on the occurrence of topologies in known structures, thus providing a manageable number of structures that can be optimized using density functional theory, and inform future experiments. This workflow is broadly applicable, correctly predicts known reticular materials, and furthermore identifies novel unknown phases for some systems.

COF↗
DOE OSTI2016

1D Co- and N-Doped Hierarchically Porous Carbon Nanotubes Derived from Bimetallic Metal Organic Framework for Efficient Oxygen and Tri-iodide Reduction Reactions

Hierarchically porous Co- and N-doped carbon nanotubes are designed as highly efficient electrocatalysts for both oxygen and tri-iodide reduction reactions via a dual-template synthesis approach. Bimetallic Zn/Co-based-zeolitic imidazolate frameworks coated on tellurium nanotubes are pyrolyzed, generating a structure with high surface area, hierarchical pore structure, abundant Co–N x active sites, and a 1D tubular graphitic carbon framework.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Highly Conductive, Lightweight, Low-Tortuosity Carbon Frameworks as Ultrathick 3D Current Collectors

The growing demand for advanced energy storage techniques and devices has driven the energy storage market to strive for higher performance, longer cycling life, and better safety. Thick electrode design enabling more electroactive materials has the potential to significantly improve the energy density on device level yet faces major challenges of slow ion transport and high deformability. In this work, inspired by natural wood materials with aligned channels along the tree growth direction, a highly conductive, lightweight, and low-tortuosity carbon framework (CF) directly carbonized from natural wood as an ultrathick 3D current collector is demonstrated. Benefiting from the uniqueness of the multichanneled CF, an ultrathick 3D electrode of lithium iron phosphate filled carbon framework with a large thickness of 800 µm and active material mass loading of 60 mg cm -2 delivers a rational capacity of 7.6 mAh cm -2 (95 Ah L -1 based on volume), long cycling life, and lower deformability with enhanced mechanical properties. This work presents a design concept for thick electrode toward high performance energy storage devices that are not limited to lithium-ion batteries.

09 BIOMASS FUELS↗
DOE OSTI2015

polyMOFs: A Class of Interconvertible Polymer-Metal-Organic-Framework Hybrid Materials

Preparation of porous materials from one-dimensional polymers is challenging because the packing of polymer chains results in a dense, non-porous arrangement. Herein, we demonstrate the remarkable adaptation of an amorphous, linear, non-porous, flexible organic polymer into a three- dimensional, highly porous, crystalline solid, as the organic component of a metal–organic framework (MOF). A polymer with aromatic dicarboxylic acids in the backbone functioned as a polymer ligand upon annealing with Zn II, generating a polymer–metal–organic framework (polyMOF). These materials break the dogma that MOFs must be prepared from small, rigid ligands. Similarly, polyMOFs contradict conventional polymer chemistry by demonstrating that linear and amorphous polymers can be readily coaxed into a highly crystalline, porous, three-dimensional structure by coordination chemistry.

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

Rapid Generation of Hierarchically Porous Metal–Organic Frameworks through Laser Photolysis

Hierarchically porous metal–organic frameworks (HP-MOFs) facilitate mass transfer due to mesoporosity while preserving the advantage of microporosity. This unique feature endows HP-MOFs with remarkable application potential in multiple fields. Recently, new methods such as linker labilization for the construction of HP-MOFs have emerged. To further enrich the synthetic toolkit of MOFs, we report a controlled photolytic removal of linkers to create mesopores within microporous MOFs at tens of milliseconds. Ultraviolet (UV) laser has been applied to eliminate “photolabile” linkers without affecting the overall crystallinity and integrity of the original framework. Presumably, the creation of mesopores can be attributed to the missing-cluster defects, which can be tuned through varying the time of laser exposure and ratio of photolabile/robust linkers. Upon laser exposure, MOF crystals shrank while metal oxide nanoparticles formed giving rise to the HP-MOFs. In addition, photolysis can also be utilized for the fabrication of complicated patterns with high precision, paving the way towards MOF lithography, which has enormous potential in sensing and catalysis.

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

A Heteromeric Carboxylic Acid Based Single-Crystalline Crosslinked Organic Framework

The development of large pore single-crystalline covalently linked organic frameworks is critical in revealing the detailed structure-property relationship with substrates. One emergent approach is to photo-crosslink hydrogen-bonded molecular crystals. Introducing complementary hydrogen-bonded carboxylic acid building blocks is promising to construct large pore networks, but these molecules often form interpenetrated networks or non-porous solids. In this report we introduced heteromeric carboxylic acid dimers to construct a non-interpenetrated molecular crystal. Crosslinking this crystal precursor with dithiols afforded a large pore single-crystalline hydrogen-bonded crosslinked organic framework H C OF-101. X-ray diffraction analysis revealed H C OF-101 as an interlayer connected hexagonal network, which possesses flexible linkages and large porous channels to host a hydrazone photoswitch. Multicycle Z/E-isomerization of the hydrazone took place reversibly within H C OF-101, showcasing the potential use of H C OF-101 for optical information storage.

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

Superior Metal‐Organic Framework Activation with Dimethyl Ether

Abstract Metal–organic frameworks (MOFs) are demonstrated to be readily activated by treatment with the low surface tension, low boiling point solvent dimethyl ether (DME). The mildness of the method enables access to high surface areas by avoiding structural changes in the framework that often plague thermal activation methods. A distinction from previous methods is that DME activation succeeds for materials with coordinatively unsaturated sites (CUS) and non‐CUS MOFs as well. DME displaces solvent molecules occupying the pores of the MOF as well as those coordinated to metal centers; reducing evacuation temperature by using a coordinating, yet highly volatile guest enables low temperature activation with structural retention as demonstrated surface area measurements that match or exceed existing activation protocols.

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

Kinetic Control via Binding Sites within the Confined Space of Metal Metalloporphyrin-Frameworks for Enhanced Shape-Selectivity Catalysis

One striking feature of enzyme is its controllable ability to trap substrates via synergistic or cooperative binding in the enzymatic pocket, which renders the shape-selectivity of product by the confined spatial environment. The success of shape-selective catalysis relies on the ability of enzyme to tune the thermodynamics and kinetics for chemical reactions. In emulation of enzyme's ability, we showcase herein a targeting strategy with the substrate being anchored on the internal pore wall of metal-organic frameworks (MOFs), taking full advantage of the sterically kinetic control to achieve shape-selectivity for the reactions. For this purpose, a series of binding site-accessible metal metalloporphyrin-frameworks (MMPFs) have been investigated to shed light on the nature of enzyme-mimic catalysis. They exhibit a different density of binding sites that are well arranged into the nanospace with corresponding distances of opposite binding sites. Furthermore, such a structural specificity results in a facile switch in selectivity from an exclusive formation of the thermodynamically stable product to the kinetic product. Thus, the proposed targeting strategy, based on the combination of porous materials and binding events, paves a new way to develop highly efficient heterogeneous catalysts for shifting selectivity.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2023

Evidence of a Uranium‐Paddlewheel Node in a Catecholate‐Based Metal–Organic Framework

Abstract The interactions between uranium and non‐innocent organic species are an essential component of fundamental uranium redox chemistry. However, they have seldom been explored in the context of multidimensional, porous materials. Uranium‐based metal–organic frameworks (MOFs) offer a new angle to study these interactions, as these self‐assembled species stabilize uranium species through immobilization by organic linkers within a crystalline framework, while potentially providing a method for adjusting metal oxidation state through coordination of non‐innocent linkers. We report the synthesis of the MOF NU‐1700 , assembled from U 4+ ‐paddlewheel nodes and catecholate‐based linkers. We propose this highly unusual structure, which contains two U 4+ ions in a paddlewheel built from four linkers—a first among uranium materials—as a result of extensive characterization via powder X‐ray diffraction (PXRD), sorption, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA), in addition to density functional theory (DFT) calculations.

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

Bio-Templated Chiral Zeolitic Imidazolate Framework for Enantioselective Chemoresistive Sensing

Chiral metal–organic frameworks (MOFs) have gained rising attention as ordered nanoporous materials for enantiomer separations, chiral catalysis, and sensing. Among those, chiral MOFs are generally obtained through complex synthetic routes by using a limited choice of reactive chiral organic precursors as the primary linkers or auxiliary ligands. Here, we report a template-controlled synthesis of chiral MOFs from achiral precursors grown on chiral nematic cellulose-derived nanostructured bio-templates. We demonstrate that chiral MOFs, specifically, zeolitic imidazolate framework (ZIF), unc-[Zn(2-MeIm) 2 , 2-MeIm=2-methylimidazole], can be grown from regular precursors within nanoporous organized chiral nematic nanocelluloses via directed assembly on twisted bundles of cellulose nanocrystals. The template-grown chiral ZIF possesses tetragonal crystal structure with chiral space group of P4 1 , which is different from traditional cubic crystal structure of I-43 m for freely grown conventional ZIF-8. The uniaxially compressed dimensions of the unit cell of templated ZIF and crystalline dimensions are signatures of this structure. We observe that the templated chiral ZIF can facilitate the enantiotropic sensing. It shows enantioselective recognition and chiral sensing abilities with a low limit of detection of 39 μM and the corresponding limit of chiral detection of 300 μM for representative chiral amino acid, D- and L- alanine.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Heterobimetallic Metal–Organic Framework as a Precursor to Prepare a Nickel/Nanoporous Carbon Composite Catalyst for 4-Nitrophenol Reduction

Nickel/nanoporous carbon (Ni/NPC) composites are facilely prepared by direct pyrolysis of nonporous heterobimetallic zinc-nickel-terephthalate frameworks (Zn1-xNixMOF, x approximate to 0-1, MOF= metal-organic framework) at 1223 K in situ. Tailoring the Ni/Zn ratio creates densely populated and small Ni nanocrystals (Ni NCs) while maintaining sufficient porosity and surface area in the final product, which exhibits the largest activity factor (9.2 s(-1)g(-1)) and excellent stability toward 4-nitrophenol reduction.

mesoporous materials↗
DOE OSTI2018

Incorporating Heavy Alkanes in Metal–Organic Frameworks for Optimizing Adsorbed Natural Gas Capacity

Metal-Organic Frameworks (MOFs) as methane adsorbents are highly promising materials for applications such as methane-powered vehicles, flare gas capture, and field natural gas separation. Pre- and post-synthetic modification of MOFs have been known to help improve both the overall methane uptake as well as the working capacity. Herein, we introduce a post-synthetic modification strategy to non-covalently modify MOF adsorbents for the enhancement of the natural gas uptake for the MOF material. In our study, we doped PCN-250 adsorbents with C 10 alkane and C 14 fatty acid, investigating their impact on the methane uptake capabilities. We found that even trace amount of heavy hydrocarbons can considerably enhance the raw methane uptake of the MOF while still being regenerable. The doped hydrocarbons are presumably located at the mesoporous defects of PCN-250, thus optimizing the framework-methane interactions. Finally, these findings reveal a general approach which can be used to modify the MOF absorbents, improving their ability to be sustainable and renewable natural gas adsorption platforms.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗