Understanding formation thermodynamics of structurally diverse zeolite oligomers with first principles calculations
Formation Thermodynamics of zeolite oligomers.
Hong, Sungil↗
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On route to one-pot synthesis of delaminated Al-SSZ-70 zeolite via partial substitution of OSDA with CTAOH surfactant
Direct synthesis of delaminated layered zeolitic materials aims to synthesize confined catalysts for reactions involving sterically bulky reactants, which are too large to benefit from conventional three-dimensional confinement in micropores.
Chemistry↗
Identification of the mechanism of NO reduction with ammonia (SCR) on zeolite catalysts
Nitrosyl ions in zeolites that form via the NO + O 2 reaction react with NH 3 to form N 2 and H 2 O (SCR reaction) via formation of transient diazo N 2 H + cation.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Free and internal energies for the adsorption of short alkanes into the zeolite SSZ-13 from ab initio molecular dynamics simulations
We useab initiomolecular dynamics simulations to calculate the temperature dependent free energy and internal energy of adsorption of short alkanes into the zeolite SSZ-13.
Chemistry↗
Inorganic synthesis-structure maps in zeolites with machine learning and crystallographic distances
Crystallographic representations and machine learning predict inorganic synthesis conditions for arbitrary zeolites, as validated with literature-mined data.
36 MATERIALS SCIENCE↗
Thermodynamic driving forces for autoreduction of Cu sites in the zeolite SSZ-13
We use phase diagrams to study the impact of auto-reduction on different Cu sites in the zeolite SSZ-13.
Chemistry↗
Static iodine loading comparisons between activated carbon, zeolite, alumina, aerogel, and xerogel sorbents
Different sorbents, including activated carbons, an aerogel, xerogels, an alumina, a zeolite, and a carbon foam were investigated for static I 2(g) loading at 71 °C for 56 d followed by 4.7 d of desorption.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Effect of defects and framework Sn on the stability and activity of Pt clusters for ethane dehydrogenation in chabazite zeolite
Framework Sn( iv ) enhances dispersion of Pt species and creates stable and efficient active sites, independent of the zeolite framework.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Selective production of para -xylene from biomass-derived 2,5-dimethylfuran through tandem Diels–Alder/dehydration reactions with a bifunctional Ga,Al-zeolite catalyst
Here we demonstrate that Ga,Al-*BEA zeolites are effective bifunctional catalysts for para -xylene ( p -xylene) production from bio-derived 2,5-dimethylfuran (DMF) through tandem Diels–Alder/dehydration reactions.
Kim, Jaeyul↗
Time-resolved dissolution elucidates the mechanism of zeolite MFI crystallization
Unbiased zeolite dissolution removes defects in the structure, enabling retroactive assessment of crystallization history.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Upgrading biocrude oil into sustainable aviation fuel using zeolite-supported iron-molybdenum carbide nanocatalysts
Food waste is an underdeveloped source for production of sustainable aviation fuel (SAF). Now, there is no certified conversion process of food waste for SAF by American Society for Testing and Materials (ASTM). We report the use of zeolite-supported molybdenum carbide nanocatalysts in upgrading biocrudes, produced from food wastes through HTL, into SAF precursors. Our data show a complete removal of oxygen from the biocrude through hydrodeoxygenation and a higher heating value of 46.5 MJ/kg, which is comparable to that of Jet A (46.1 MJ/kg). The prescreening tests (tier alpha and beta) show the average carbon number of the distillation cut (150° to 230°C) of upgraded fuel is 10.6, close to the value of 11.4 for average conventional jet fuel, and the specifications of properties including surface tension, viscosity, heating value, flash point, and freezing point were found to meet the standards of SAF. The metal carbide nanocatalysts were reusable in upgrading tests, and the activity of deoxygenation was retained.
10 SYNTHETIC FUELS↗
Factors Controlling Electrochemistry-Induced Deposition of a Zeolitic Imidazolate Framework-8 Film on Underlying Substrates
This paper discusses factors controlling electrochemistry-induced deposition of a zeolitic imidazolate framework-8 (ZIF-8) film on a planar substrate that is placed under an electrode. This method, which was recently demonstrated by us [T. Ito, et al. Cryst. Growth Des., 23, 6369 (2023)], provides a simple means to form a ZIF-8 film having lateral dimensions replicating those of a working electrode on an underlying substrate. We reported the effects of applied cathodic potential, electrode–substrate distance, and deposition time on the film formation, and proposed a mechanism involving cathodic base generation at a working electrode that promoted ligand deprotonation to form intermediate species, followed by their diffusion toward an underlying substrate. Here, we discuss details on the deposition mechanism by investigating the influences of other factors on the film deposition. We have investigated the effects of precursor concentration on film formation, and clarified that O 2 is a probase, rather than H 2 O. We have also shown the influences of substrate surface properties controlled by self-assembled monolayers on film thickness and morphology. Most notably, we successfully demonstrated the formation of microscale ZIF-8 films using an ultramicroelectrode, revealing the applicability of the electrochemistry-induced method for micropatterned film deposition on an underlying substrate.
36 MATERIALS SCIENCE↗
Data for: "Inorganic synthesis-structure maps in zeolites with machine learning..."
Repository containing all the data necessary to reproduce the paper "Inorganic synthesis-structure maps in zeolites with machine learning and crystallographic distances". This content includes: raw data for all results in the article; figures appearing in the main paper; and Jupyter notebooks and scripts containing the code for analyzing/reproducing the results.
Schwalbe Koda, Daniel↗
Fundamental Understanding of Cu-zeolite SCR Catalyst Aging Mechanism (CRADA 452)
The CRADA between Cummins and Pacific Northwest National Laboratory (PNNL) will focus on advanced emission control for high-efficiency engines. It will specifically focus on the following three areas: 1. Passive NOx absorbers - The purpose is to develop next generation materials that can be efficiently used to address the cold-operation, as driven by improved engine efficiency. 2. Oxidation of methane and short alkanes – The purpose is to address cold-operation emissions arising from CNG vehicles. 3. Improved understanding of particulates–the purpose is to understand how particulates are formed which will be used to develop strategies to address the tightening regulations and their enforcement for exhaust particulate matter. The first two areas will be based on PNNL’s technical leadership in the area of zeolite-based materials. The third area will have a shorter time scope to leverage the unique SPLAT capabilities at PNNL to help address Cummins’ needs in improving the understanding of particulates.
33 ADVANCED PROPULSION SYSTEMS↗
Synthesis and characterization of zeolite sorbents from coal fly ash by a microwave-assisted hydrothermal method for removal of boron leachate from coal impoundments
This study developed promoted zeolite-based sorbents derived from coal fly ash to remove leachates (like boron) from ash impoundment or landfill to protect the environment and reuse legacy coal ash. The sorbents were synthesized using machine learning model results as guide to accelerate the sorbent development.
Wang, Ping↗
Synthesis of nanodiamonds encapsulated by zeolitic imidazole framework-8 for quantum sensing applications
Nitrogen vacancy (NV)-containing nanodiamonds are widely used in quantum sensing applications due to their high sensitivity to magnetic fields, relatively low cost, and ability to be initialized, manipulated, and read out at room temperature. Quantum sensing techniques such as optically detected magnetic resonance (ODMR) and spin relaxometry have exploited the sensitivity of the NV nanodiamonds to magnetic fields to detect a range of analytes, such as pH, metal ions, and biomolecules. However, diversifying the sensing targets accessible by NV diamond quantum sensors typically requires careful engineering of the diamond surface chemistry with stimuli-responsive functional groups. Here, a simple protocol for coating NV nanodiamonds with the zeolitic imidazole framework 8 (ZIF-8), a widely used metal-organic framework, is presented. ZIF-8 is a highly porous material that has been used as a selective sensor for gasses, metal ions, and other analytes. The material is well-characterized by x-ray diffraction, transmission electron microscopy, scanning electron microscopy, x-ray photoelectron spectroscopy, and luminescence spectroscopy. Encapsulation of NV nanodiamonds with a porous scaffold such as ZIF-8 provides a promising method for improving the selectivity for the quantum sensing of various analytes. Importantly, the ZIF-8 coating does not impact the luminescence properties of the NV diamond, which is a key readout in ODMR and spin relaxometry sensing approaches. Indeed, the ODMR spectra with and without the ZIF-8 shell is nearly identical. Moreover, the ZIF-8 coating increases the longitudinal spin relaxation time of the NV nanodiamond by a factor of 4 relative to aggregated diamond, a desirable outcome for spin relaxation-based quantum sensing. Metal-organic framework composites with nanodiamonds thus are an exciting strategy for enhancing NV nanodiamond performance in applications such as quantum sensing and quantum-enhanced nuclear magnetic resonance spectroscopy.
nitrogen vacancy nanodiamond↗
Collaborative: Fundamental studies of how water influences the synthesis and behavior of zeolite catalysts for reactions in the circular carbon economy (Final Technical Report)
This project established a computational framework to predict and interpret how synthesis conditions control active site location in MFI zeolites and how those site distributions influence catalytic reactivity. The Hibbitts Group led the theoretical effort, applying periodic DFT calculations to quantify (i) SDA–framework–heteroatom interactions during crystallization and (ii) the energetics and mechanisms of arene methylation reactions within distinct MFI environments.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Formation of Zeolites Responsible for Waste Glass Rate Acceleration: An Experimental and Computational Study for Understanding Thermodynamic and Kinetic Processes
This report summarizes work on the NEUP Project 18-15496, DE-NE0008774 (Formation of Zeolites Responsible for Waste Glass Rate Acceleration: An Experimental and Computational Study for Understanding Thermodynamic and Kinetic Processes). The content of the report is from four journal articles that resulted from work on the project.
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗