Rh K-Edge High-Energy-Resolution Fluorescence-Detected X-ray Absorption Near-Edge Structure Spectroscopy Reveals Deactivated RhAlO_x Structure in Aged Rh/γ-Al₂O₃ Catalyst

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 6466 - 6472

Published: April 6, 2025

Language: Английский

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Metal-zeolite catalysts promoting low-temperature methane oxidation to oxygenates

Chemical Synthesis, Journal Year: 2025, Volume and Issue: 5(3)

Published: April 17, 2025

Catalytic conversion of methane (CH4) into value-added chemicals provides a viable path to reduce dependency on crude oil. Despite the challenges associated with activating methane’s C–H bond and limiting side reactions, low-temperature oxidation oxygenates has emerged as promising approach, often hailed “grail reaction”. Zeolite-based metal (metal-zeolite) catalysts facilitate at low temperatures, converting while minimizing complete carbon dioxide (CO2). This review highlights recent achievements in metal-zeolite for partial coupling oxidation. With zeolite core, we explore synthesis methods, metallic active sites, reaction mechanisms, descriptors Additionally, examine critical role mono- bi-metallic species monoxide (CO). Finally, discuss opportunities under mild conditions, proposing future directions rational design catalysts, revealing mechanisms through operando or situ techniques, leveraging artificial intelligence (AI) enhanced catalytic efficiency.

Language: Английский

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Recent advances in ambient electrochemical methane conversion to oxygenates using metal oxide electrocatalysts

Green Chemistry, Journal Year: 2023, Volume and Issue: 26(2), P. 655 - 677

Published: Dec. 6, 2023

In this review, the recent developments in electrocatalytic conversion of methane under ambient conditions, with focus on metal oxide catalysts, are examined. The commonly employed strategies systematically reviewed.

Language: Английский

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Bayesian-Optimization-Based Improvement of Cu-CHA Catalysts for Direct Partial Oxidation of CH₄

The Journal of Physical Chemistry C, Journal Year: 2022, Volume and Issue: 126(46), P. 19660 - 19666

Published: Nov. 9, 2022

In the present study, catalytic performance of a Cu zeolite for partial CH4 oxidation is improved by refinement catalyst composition using Bayesian optimization method. For application to this challenging reaction, activity needs be while maintaining its selectivity products; thus, both and are set as objective variables in study. Accordingly, model describing how affects prepared from an experimental data Optimal compositions identified evaluated experimentally, expected improvement (EI) updated another cycle newly obtained data. This trial repeated until proposed optimal confirmed experimentally. work, Cu-CHA zeolites used because they show relatively high performances among various zeolites. catalysts having Cu-ion exchange rates (Cu IERs) four different Si/Al2 ratios (5.2, 7.2, 10, 19.5) synthesized CH4–O2–H2O flow reactor experiments. The process achieved Cu-IER only two cycles 22 Therefore, demonstrated means improve oxidation.

Language: Английский

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Continuous selective conversion of methane to methanol over a Cu-KFI zeolite catalyst using a water–O₂ mixture as the oxygen source

Chemical Communications, Journal Year: 2023, Volume and Issue: 60(2), P. 228 - 231

Published: Nov. 29, 2023

The article highlights the potential of Cu-KFI zeolites as catalysts in continuous conversion methane to methanol using water and O 2 oxidants.

Language: Английский

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Cis-trans adsorption configuration influenced high-efficient hydrogenation of furfural over zeolite-encapsulated PtCu bimetallic catalyst

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: 489, P. 151471 - 151471

Published: April 19, 2024

Language: Английский

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ABO₄ as an Active Catalyst Structure for Direct Partial CH₄ Oxidation as Identified through Screening of Supported Catalysts

ACS Catalysis, Journal Year: 2024, Volume and Issue: 15(2), P. 697 - 705

Published: Dec. 24, 2024

In the present study, 76 different metal-oxide-supported-transition-metal catalysts were prepared using 11 metal oxides (MgO, Al2O3, SiO2, TiO2, V2O5, ZrO2, Nb2O5, MoO3, Ta2O5, WO3, and La2O3) seven 3d metals (V, Mn, Fe, Co, Ni, Cu, Zn). The supported catalysts, along with single oxides, screened to identify catalytically active lattice oxygen structures for partial oxidation of CH4 formaldehyde methanol. Fe/MoO3, Fe/V2O5, particularly Fe/Nb2O5 found be highly effective. Structural analysis Fe sites in was performed high-energy-resolution-fluorescence-detected K-edge X-ray absorption near-edge structure spectroscopy, revealing that FeNbO4, FeMoO4, FeVO4 species Fe/Nb2O5, respectively, are responsible their partial-oxidation activities. contrast, Fe2O3 formed Fe/Al2O3, Fe/SiO2, Fe/Ta2O5, Fe/WO3 complete CO2 than oxidation, as MgFe2O4, LaFeO3, TiFe2O5 Fe/MgO, Fe/La2O3, Fe/TiO2, interstitial solid solution Fe3+ ZrO2 generated Fe/ZrO2. Furthermore, while Fe/WO4 ineffective FeWO4 by a hydrothermal method exhibits high selectivity oxidation. Additionally, previous studies have shown CuWO4 CuMoO4 Accordingly, ABO4 (where A is B group 5 or 6 metal) indicated viable design basis development

Language: Английский

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Transition-Metal-Promoted Cu-SSZ-13 Catalysts for Continuous Selective Oxidation of Methane to Methanol Using Molecular Oxygen

ACS Catalysis, Journal Year: 2023, Volume and Issue: 14(1), P. 292 - 298

Published: Dec. 15, 2023

Chabazite-type Cu-SSZ-13 zeolites can catalyze the continuous selective oxidation of methane (CH4) to methanol (CH3OH) under mild conditions using molecular oxygen (O2) as oxidant. Here, we demonstrate that addition Fe and Zn into zeolite led an increase in space–time CH3OH yield by 138% 68%, respectively, CH4-to-CH3OH reaction. Comparative investigations were conducted over pristine Fe-loaded various ex situ methods, including X-ray absorption spectroscopy, infrared ultraviolet–visible Raman etc., revealed promoted transformation Cu2+ sites [Cu(OH)]+, precursor binuclear [Cu(trans-μ-1,2-O2)Cu]2+ species, which is highly active for oxidation.

Language: Английский

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Deciphering the Local Environment of Electrocatalytic Metal Sites with X‐ray Absorption Fine Structure

Small Structures, Journal Year: 2024, Volume and Issue: 5(6)

Published: March 15, 2024

Electrocatalysis plays a pivotal role in energy conversion and holds significant promise for the development of new sources. Understanding intricate atomic‐level interplay between active sites electrocatalytic activity is essential comprehending catalytic behavior advancing high‐performance catalysts. In this review, an overview recent advances X‐ray absorption fine structure (XAFS) provided deciphering local environment metal sites. The application XAFS disclosing electronic interaction coordination summarized, offering insights into correlation ligand arrangement activity. Special attention given to advanced techniques exploring species, including determining actual sites, monitoring transformation, sites–catalysis relationship. limitations traditional have naturally prompted high‐spatiotemporal‐resolution high‐energy‐resolution as well in‐situ/ operando methods better understand entire process. This review anticipated provide comprehensive understanding capabilities electrocatalysts, with implications design materials.

Language: Английский

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Oxidase-Mimetic Nanocatalyst Based on Geometry-Dependent Biomolecular Self-Assembly

Chemistry of Materials, Journal Year: 2023, Volume and Issue: 35(24), P. 10515 - 10523

Published: Dec. 13, 2023

Enzymes rely on protein folding to create functional sites essential for their catalytic activity. Reproducing enzymatic active in artificial systems has been difficult due the intricate patterns that enzymes demonstrate. Inspired by natural systems, we developed a supramolecular copper-cluster-dependent catechol oxidase. This system is constructed through self-assembly of flavin adenine dinucleotide (FAD) with fluorenylmethyloxycarbonyl-modified amino acids (e.g., Fmoc-lysine) and Cu2+ ions. Fmoc-amino self-associate fluorenyl stacking, facilitating formation oxidase-mimetic copper clusters. FAD self-assembles via aromatic enabling incorporation acid groups form coordination sphere around Cu2+. The enhances oxidase-like activity over 100-fold. It estimated each can catalyze transformation ca. 80 substrate molecules within 15 min. catalyst demonstrated thermophilic properties excellent storage stability. When exposed 460 nm light, FAD/Fmoc-K/Cu2+ complex further enhanced, potentially cooperative interaction between lumichrome generated from photodegradation. These findings have implications design advanced enzyme-mimetic catalysts.

Language: Английский

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