First-Principles Simulation of Active Site Selectivity for CO2 and H2 Adsorption on Mg(OH)+/Mg2+ and Ca(OH)+/Ca2+ Zeolites DOI
Pragnya Paramita Samal, Saïlaja Krishnamurty

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 11, 2024

One very effective strategy for addressing global warming and transitioning to sustainable energy sources is selective CO2 separation over H2. Porous materials, particularly zeolites, have demonstrated enormous potential energy-efficient techniques combined with storage. By altering interactions at cation-binding sites, zeolite's gas adsorption characteristics toward carbon capture can be improved. In this study, Mg Ca are assessed as extra-framework cations in divalent (Ca2+, Mg2+) monovalent states (Ca(OH)+, Mg(OH)+) faujasite chabazite zeolites The study also explores the impact of mixed cations, viz., a combination both Ca2+ Mg2+ framework, on their potential. This uses DFT dispersion corrections calculate energies, enthalpies, Gibb's free energies adsorbed H2 molecules. Among parameters evaluated, D4, TS/HI, MBD, D4 approaches experimental accuracy. general, trend obtained FAU > CHA Mg(OH)+ Ca(OH)+ CHA. heats using PBE+D4 −46 kJ/mol −10 FAU, respectively. These values closely align results −45 −6 kJ/mol, respectively, within chemical accuracy limit ±4 kJ/mol. relative suggest that CHA, there exists minimum difference 26 between Hence, piece work highlights six-membered cage viable substitute replace, current best candidate literature, Li+, capture.

Language: Английский

Exploring the Impact of Active Site Structure on the Conversion of Methane to Methanol in Cu‐Exchanged Zeolites DOI Creative Commons
Florian Göltl, Saurabh Bhandari, Edgard A. Lebrón‐Rodríguez

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(23)

Published: April 4, 2024

Abstract In the past, Cu‐oxo or ‐hydroxy clusters hosted in zeolites have been suggested to enable selective conversion of methane methanol, but impact active site's stoichiometry and structure on methanol production is still poorly understood. Herein, we apply theoretical modeling conjunction with experiments study these two factors partial oxidation Cu‐exchanged zeolite SSZ‐13. Phase diagrams developed from first‐principles suggest that Cu‐hydroxy dimers are stabilized when O 2 N used activate catalyst, respectively. We confirm predictions experimentally determine a stepwise process, can convert twice as much compared Cu‐hydroxyl dimers. Our models rationalize how Cu‐di‐oxo up molecules while Cu‐di‐hydroxyl only one molecule per catalytic cycle. These findings imply Cu clusters, at least oxo group hydroxyl groups needed This simple structure–activity relationship allows intuitively understand potential small oxygenated hydroxylated transition metal methanol.

Language: Английский

Citations

11
Structure and Reactivity of Binuclear Cu Active Sites in Cu-CHA Zeolites for Stoichiometric Partial Methane Oxidation to Methanol DOI

Laura N. Wilcox,

José Rebolledo-Oyarce, Andrew D. Mikes

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(5), P. 3647 - 3663

Published: Feb. 21, 2024

Aluminosilicate zeolites exchanged with copper ions facilitate partial methane oxidation (PMO) to methanol in stoichiometric and reduction cycles, yet the identities of active Cu sites details reaction mechanism remain debated. Here, we use high-symmetry chabazite (CHA) zeolite framework as a model support probe relationship between bulk composition, speciation, response various oxidizing reducing treatments. Density functional theory first-principles thermodynamics combined statistical models reveal that speciation composition depend strongly on Al configuration external gas conditions. Cu-CHA samples were synthesized survey broad regions Si/Al Cu/Al space proximity. Characterization by situ X-ray absorption UV–visible spectroscopy during exposure different conditions extent is sensitive activation thus both kinetic thermodynamic factors influence oxidizability given material. Similar characterizations CO titrates Cu2+ amounts suggesting presence O- O2-bridged species. In contrast, CH4 autoreduction (He) treatments reduce similar but smaller numbers than CO, implicating dimers potential common intermediate former pathways. A systematic increase yields (per Cu) PMO cycles fraction binuclear Ox-bridged suggests these species sites, depicted an updated mechanism.

Language: Английский

Citations

8
Copper–oxygen adducts: new trends in characterization and properties towards C–H activation DOI Creative Commons
Jonathan De Tovar, Rébecca Leblay, Yongxing Wang

et al.

Chemical Science, Journal Year: 2024, Volume and Issue: 15(27), P. 10308 - 10349

Published: Jan. 1, 2024

Recent progresses in Cu–oxygen adducts towards recalcitrant C–H activation are reviewed with focus on Cu metalloenzymes and bioinspired synthetic models, mono- to polynuclear complexes, working under homogeneous heterogeneous catalytic conditions.

Language: Английский

Citations

5
Quantifying the Hydration‐Dependent Dynamics of Copper Migration and Activity in Zeolite Omega for the Partial Oxidation of Methane DOI Creative Commons
Johannes Wieser, Dariusz Wardecki, Jörg W. A. Fischer

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(49)

Published: Aug. 13, 2024

Abstract Copper‐exchanged zeolite omega (Cu‐omega) is a potent material for the selective conversion of methane‐to‐methanol (MtM) via oxygen looping approach. However, its performance exhibits substantial variation depending on operational conditions. Under an isothermal temperature regime, Cu‐omega demonstrates subdued activity below 230 °C, but experiences remarkable increase in at 290 °C. Applying high‐temperature activation protocol 450 °C causes rapid deactivation material. This behavioral divergence investigated by combining reactivity studies, neutron diffraction and situ high‐resolution anomalous X‐ray powder (HR‐AXRPD), as well electron paramagnetic resonance spectroscopy, to reveal that migration Cu throughout framework primary cause these behaviors, which turn predominantly governed degree hydration system. work suggests control over may be harnessed significantly generating more active sites MtM conversion. These results underscore power HR‐AXRPD unraveling behavior materials under reaction conditions suggest re‐evaluation Cu‐zeolites priorly deemed inactive across broader range protocols warranted.

Language: Английский

Citations

4
First-Principles Thermodynamic Background of the Comprehensive Reaction Network of NO Oxidation over CuSSZ-13 Catalysts─Influence of Copper Speciation and Interpretation of TPD and TPSR Profiles DOI Creative Commons
Bartosz Mozgawa, Filip Zasada, Monika Fedyna

et al.

ACS Catalysis, Journal Year: 2025, Volume and Issue: 15(4), P. 2715 - 2734

Published: Jan. 30, 2025

A thorough molecular DFT modeling coupled with first-principles thermodynamic (FPT), spectroscopic (EPR/IR), and catalytic investigations into a complex network of reactions involved in the interaction NO O2 comprehensive variety active centers present CuSSZ-13 zeolites (Cu2+, Cu+, Cu2+–OH–, Cu2+–O2––Cu2+, Cu2+–O22––Cu2+, segregated CuO) were carried out. The structure, energetics, electronic magnetic properties identified profuse adspecies intermediates ascertained. Their thermal stability reactivity at wide range experimental conditions interpreted by using constructed ΔG(p,T) diagrams. course selective oxidation (NO–SCO) 16O2 or 18O2 was examined temperature-programmed surface reaction (TPSR) two types catalysts intentionally diverse copper speciation. results obtained, supported corroborative IR EPR measurements, revealed multiple pathways interactions single Cu2+–OH–) dual (Cu2+–O2––Cu2+, Cu2+–O22––Cu2+) 6MR 8MR topologies CuO. temperature behavior critical (HONO, nitrate, nitrite), their evolvement routes NO2, rationalized calculated FPT profiles. unraveled classified metal (cationic) redox, ligand (anionic) HONO redox cycles. Cu2+–OH– species as prime for formation NO2 via pathway. elusive allow chemical communication between individual Depending on actual conditions, can act reduction agent Cu2+ electroprotic source nitrites upon deprotonation, an oxidant Cu+ H2O NO. For pathway, significant difference cations accommodated 6MRs 8MRs observed, Cu2+/6MR being spectators Cu2+/8MR species. Dimeric bridging oxo peroxy moieties produce nitrates mechanisms. Segregated CuO nanocrystals contribute to only high temperatures (T > 400 °C), leading isotopic scrambling 18O-labeled oxygen nitric oxide. established successfully used clarify dependence NO–SCO profiles, also providing suitable mechanistic background interpreting nature oxidative half-cycle over Cu-SSZ-13 catalysts.

Language: Английский

Citations

0
AI-empowered digital design of zeolites: Progress, challenges, and perspectives DOI Creative Commons
Mengfan Wu, Shiyi Zhang, Jie Ren

et al.

APL Materials, Journal Year: 2025, Volume and Issue: 13(2)

Published: Feb. 1, 2025

The rise of artificial intelligence (AI) as a powerful research tool in materials science has been extensively acknowledged. Particularly, exploring zeolites with target properties is vital significance for industrial applications, integrating AI technologies into zeolite design undoubtedly brings immense promise the advancements this field. Here, we provide comprehensive review AI-empowered digital zeolites. It showcases state-of-the-art progress predicting zeolite-related properties, employing machine learning potentials simulations, using generative models inverse design, and aiding experimental synthesis challenges perspectives are also discussed, emphasizing new opportunities at intersection This expected to offer crucial guidance advancing innovations through future.

Language: Английский

Citations

0
Insights into the nuclearity and local environment of transition metal species in ion-exchanged CHA zeolites and effects on the oxidation of methane DOI Creative Commons
Toshiyuki Yokoi, Peipei Xiao, Lizhuo Wang

et al.

Research Square (Research Square), Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 12, 2025

Abstract Ion-exchange method is a popular and facile way to prepare metal-containing zeolites, transition-metal-exchanged zeolites have been widely used for the activation of small molecules such as CO₂, CH₄, NH3, focusing on their transformation into valuable products or environmentally friendly chemicals. Understanding exchange between metal ions zeolite inferring local environment species crucial comprehending predicting activity metal-exchanged catalysts. Herein, frequently employed early transition metals (Fe3+, Co2+, Cu2+) were adopted with CHA-type aluminosilicate (SSZ-13). The acidity CHA was measured by NH3-TPD, speciation identified HAADF-STEM images, UV-vis, XAS spectra. linear trend line strong acid content metal/Al ratio exchanged catalysts calculate ion-exchanged degree cations acidic protons zeolite. ratios n:1 (n˃2), 1:2, 1:1 Fe, Co, Cu/CHA specified possible nuclearity species. Therefore, these exhibited completely different reaction characteristics toward direct continuous oxidation methane using N2O oxidant. Taking full advantage features, high performance in decomposition, conversion hydrocarbon via methanol intermediate, selectivity realized Cu-exchanged respectively. These findings provide guidance reference preparing metal-ion-exchanged suitable applications.

Language: Английский

Citations

0
Application of Machine Learning Interatomic Potentials in Heterogeneous Catalysis DOI

Gbolagade Olajide,

Khagendra Baral, Sophia Ezendu

et al.

Published: Jan. 1, 2025

Language: Английский

Citations

0
Predicting CO adsorption sites in Co-doped zeolite via density functional theory calculations DOI
М. И. Шилина, Igor P. Gloriozov

Materials Chemistry and Physics, Journal Year: 2025, Volume and Issue: unknown, P. 130893 - 130893

Published: April 1, 2025

Language: Английский

Citations

0
Metal-zeolite catalysts promoting low-temperature methane oxidation to oxygenates DOI Open Access
Bingbing Xiang, Jialiang Li,

Bokun Chang

et al.

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

Citations

0