Selective Oxidative Dehydrogenation of Ethane and Propane over Copper‐Containing Mordenite: Insights into Reaction Mechanism and Product Protection DOI Creative Commons
Mikalai A. Artsiusheuski, René Verel, Jeroen A. van Bokhoven

и другие.

Angewandte Chemie, Год журнала: 2023, Номер 135(44)

Опубликована: Сен. 12, 2023

Abstract Copper(II)‐containing mordenite (CuMOR) is capable of activation C−H bonds in C 1 ‐C 3 alkanes, albeit there are remarkable differences between the functionalization ethane and propane compared to methane. The reaction with CuMOR results formation ethylene propylene, while methane predominantly yields methanol dimethyl ether. By combining situ FTIR MAS NMR spectroscopies as well time‐resolved Cu K‐edge X‐ray absorption spectroscopy, mechanism was derived, which differs significantly for each alkane. propylene proceeds via oxidative dehydrogenation corresponding alkanes selectivity above 95 % 85 propane. stable π‐complexes olefins I sites, formed upon reduction II ‐oxo species, protects from further oxidation and/or oligomerization. This different methane, hydroxylation leading surface methoxy species bonded zeolite framework. Our findings constitute one major steps direct conversion important commodities open a novel research direction aiming at selective synthesis olefins.

Язык: Английский

Competition between Mononuclear and Binuclear Copper Sites across Different Zeolite Topologies DOI Creative Commons
Asanka Wijerathne,

Allison M. Sawyer,

Rohil Daya

и другие.

JACS Au, Год журнала: 2024, Номер 4(1), С. 197 - 215

Опубликована: Янв. 4, 2024

A key challenge for metal-exchanged zeolites is the determination of metal cation speciation and nuclearity under synthesis reaction conditions. Copper-exchanged zeolites, which are widely used in automotive emissions control potential catalysts partial methane oxidation, have particular evidenced a wide variety Cu structures that observed to change with exposure conditions, zeolite composition, topology. Here, we develop predictive models CHA, MOR, BEA, AFX, FER topologies using interatomic potentials, quantum chemical calculations, Monte Carlo simulations interrogate this vast configurational compositional space. Model predictions rationalize experimentally differences between Cu-zeolites wide-body literature, including populations, structural variations, methanol per yields. Our results show both topological features commonly Al-siting biases MOR increase population binuclear sites, explaining small mononuclear sites these materials relative other such as CHA BEA. Finally, machine learning classification model determine preference form or at different Al configurations 200 international database. reveal several extreme ends vs spectrum, highlighting synthetic options realization strong preferences.

Язык: Английский

Процитировано

20
Selective Oxidative Dehydrogenation of Ethane and Propane over Copper‐Containing Mordenite: Insights into Reaction Mechanism and Product Protection DOI Creative Commons
Mikalai A. Artsiusheuski, René Verel, Jeroen A. van Bokhoven

и другие.

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(44)

Опубликована: Сен. 12, 2023

Copper(II)-containing mordenite (CuMOR) is capable of activation C-H bonds in C1 -C3 alkanes, albeit there are remarkable differences between the functionalization ethane and propane compared to methane. The reaction with CuMOR results formation ethylene propylene, while methane predominantly yields methanol dimethyl ether. By combining situ FTIR MAS NMR spectroscopies as well time-resolved Cu K-edge X-ray absorption spectroscopy, mechanism was derived, which differs significantly for each alkane. propylene proceeds via oxidative dehydrogenation corresponding alkanes selectivity above 95 % 85 propane. stable π-complexes olefins CuI sites, formed upon reduction CuII -oxo species, protects from further oxidation and/or oligomerization. This different methane, hydroxylation leading surface methoxy species bonded zeolite framework. Our findings constitute one major steps direct conversion important commodities open a novel research direction aiming at selective synthesis olefins.

Язык: Английский

Процитировано

19
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

и другие.

ACS Catalysis, Год журнала: 2024, Номер 14(5), С. 3647 - 3663

Опубликована: Фев. 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.

Язык: Английский

Процитировано

8
Broadly tunable filter based on a graphene MEMS-photonic crystal composite structure and its application in single-pixel full-color displays DOI
Wenjing Liu, Guanghui Li,

Chaomeng Chen

и другие.

Journal of Materials Chemistry C, Год журнала: 2024, Номер 12(18), С. 6588 - 6595

Опубликована: Янв. 1, 2024

A graphene MEMS tunable narrowband filter with minimal deformation (<2 pm), high voltage sensitivity (>400 nm V −1 ), bandwidth (>200 nm) was proposed, achieving full-color display within a single pixel, color gamut reaching 214% of sRGB.

Язык: Английский

Процитировано

6
Progress of independent component analysis and its recent application in spectroscopy quantitative analysis DOI
Yankun Li,

M. Zhang,

Xihui Bian

и другие.

Microchemical Journal, Год журнала: 2024, Номер 202, С. 110836 - 110836

Опубликована: Май 21, 2024

Язык: Английский

Процитировано

5
Pinpointing Cu-Coordination Motifs in Bio-Inspired MOFs by Combining DFT-Assisted XAS Analysis and Multivariate Curve Resolution DOI Creative Commons

Beatrice Garetto,

Ning Cao, Valeria Finelli

и другие.

The Journal of Physical Chemistry C, Год журнала: 2025, Номер unknown

Опубликована: Фев. 6, 2025

In recent years, X-ray absorption spectroscopy (XAS) has emerged as an essential technique for investigating the structure and composition of heterogeneous catalysts, providing valuable insights into nature active sites within these systems. However, average XAS signal, inherently merged over all absorber-containing species forming during in situ/operando experiments, often complicates interpretation data. Nonetheless, advanced analysis methods have been developed to address this problem. particular, herein we employed situ together with multivariate curve resolution-alternating least squares (MCR-ALS) wavelet transform (WT) monitor evolution distinct Cu histidine-modified Cu-UiO-66 MOFs obtain detailed structural about sites. A novel approach adopted work was application density functional theory (DFT)-assisted extended fine (EXAFS) fitting quantitatively refine local MCR-derived pure species. This revealed preferential redox activity CuII ions coordinated defective Zr clusters MOF, compared bound both histidine molecule site a standard reaction protocol.

Язык: Английский

Процитировано

0
Low-Temperature Nonoxidative Dehydrogenation of Short-Chain Alkanes over Copper(I) Mordenite via Chemical Looping DOI
Mikalai A. Artsiusheuski, Jiawei Guo, Ambarish Kulkarni

и другие.

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Апрель 24, 2025

We report selective low-temperature non-oxidative dehydrogenation of ethane and propane to ethylene propylene via chemical looping using copper(I)-containing mordenite as active material. Combining Cu K-edge X-ray absorption spectroscopy, in situ infrared spectroscopy (FTIR), H/D kinetic isotope effect measurements, density functional theory calculations, we show that the sites for reaction are copper(I) cations hosted zeolite framework, rate-limiting step is activation first C-H bond alkane. The stoichiometric between gas-phase alkane cationic site results formation a stable copper(I)-alkene π-complex gaseous hydrogen. Complete saturation with alkenes can be attained at 573 K selectivity close 100%. strong binding promotes reaction, enabling yield alkene more than 100 times greater thermodynamic limit. Copper(I)-alkene complexes decomposed separate by contact water near-ambient temperature, releasing into gas phase, material regenerated without detectable loss activity.

Язык: Английский

Процитировано

0
Mechanistic Studies of Continuous Partial Methane Oxidation on Cu−Zeolites Using Kinetic and Spectroscopic Methods DOI Creative Commons
Andrew D. Mikes, Lauren Kilburn, Rajamani Gounder

и другие.

ChemCatChem, Год журнала: 2024, Номер 16(15)

Опубликована: Март 11, 2024

Abstract Over the past few decades, a significant amount of research effort has focused on investigating active site requirements and reaction mechanisms for partial methane oxidation (PMO) to methanol over copper–exchanged zeolites during stoichiometric stepwise chemical looping routes. More recently, efforts have expanded include PMO in continuous catalytic regime, primarily focusing determining influence catalyst composition Cu speciation structure and, turn, rate selectivity. The structures candidate sites are commonly studied using combination ex situ spectroscopic approaches. In this perspective, we critically examine prior literature Cu–zeolites identify key knowledge gaps that remain our understanding as motivation future efforts. We opportunities address these by adapting analogous interrogation techniques been successfully used elucidate mechanistic details another redox cycle Cu–zeolites, selective reduction (SCR) nitrogen oxides (NO x ).

Язык: Английский

Процитировано

0
Detection and Characterization of Hydride Ligands in Copper Complexes by Hard X‐Ray Spectroscopy DOI Creative Commons
Lorena Fritsch,

Pia Rehsies,

Waël Barakat

и другие.

Chemistry - A European Journal, Год журнала: 2024, Номер 30(36)

Опубликована: Апрель 23, 2024

Transition metal complexes, particularly copper hydrides, play an important role in various catalytic processes and molecular inorganic chemistry. This study employs synchrotron hard X-ray spectroscopy to gain insights into the geometric electronic properties of hydrides as potential catalysts for CO

Язык: Английский

Процитировано

0
Selective Oxidative Dehydrogenation of Ethane and Propane over Copper‐Containing Mordenite: Insights into Reaction Mechanism and Product Protection DOI Creative Commons
Mikalai A. Artsiusheuski, René Verel, Jeroen A. van Bokhoven

и другие.

Angewandte Chemie, Год журнала: 2023, Номер 135(44)

Опубликована: Сен. 12, 2023

Abstract Copper(II)‐containing mordenite (CuMOR) is capable of activation C−H bonds in C 1 ‐C 3 alkanes, albeit there are remarkable differences between the functionalization ethane and propane compared to methane. The reaction with CuMOR results formation ethylene propylene, while methane predominantly yields methanol dimethyl ether. By combining situ FTIR MAS NMR spectroscopies as well time‐resolved Cu K‐edge X‐ray absorption spectroscopy, mechanism was derived, which differs significantly for each alkane. propylene proceeds via oxidative dehydrogenation corresponding alkanes selectivity above 95 % 85 propane. stable π‐complexes olefins I sites, formed upon reduction II ‐oxo species, protects from further oxidation and/or oligomerization. This different methane, hydroxylation leading surface methoxy species bonded zeolite framework. Our findings constitute one major steps direct conversion important commodities open a novel research direction aiming at selective synthesis olefins.

Язык: Английский

Процитировано

0