A selective Au-ZnO/TiO2 hybrid photocatalyst for oxidative coupling of methane to ethane with dioxygen

Nature Catalysis, Год журнала: 2021, Номер 4(12), С. 1032 - 1042

Опубликована: Ноя. 29, 2021

Язык: Английский

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Methane transformation by photocatalysis

Nature Reviews Materials, Год журнала: 2022, Номер 7(8), С. 617 - 632

Опубликована: Фев. 28, 2022

Язык: Английский

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Pd-Modified ZnO–Au Enabling Alkoxy Intermediates Formation and Dehydrogenation for Photocatalytic Conversion of Methane to Ethylene

Journal of the American Chemical Society, Год журнала: 2020, Номер 143(1), С. 269 - 278

Опубликована: Дек. 29, 2020

Photocatalysis provides an intriguing approach for the conversion of methane to multicarbon (C2+) compounds under mild conditions; however, with methyl radicals as sole reaction intermediate, current C2+ products are dominated by ethane, a negligible selectivity toward ethylene, which, key chemical feedstock, possesses higher added value than ethane. Herein, we report direct photocatalytic methane-to-ethylene pathway involving formation and dehydrogenation alkoxy (i.e., methoxy ethoxy) intermediates over Pd-modified ZnO–Au hybrid catalyst. On basis various in situ characterizations, it is revealed that Pd-induced capability catalyst holds turning on pathway. During reaction, molecules first dissociated into surface ZnO assistance Pd. Then these further dehydrogenated coupled radical ethoxy, which can be subsequently converted ethylene through dehydrogenation. As result, optimized ZnO–AuPd atomically dispersed Pd sites Au lattice achieves 536.0 μmol g–1 compound 96.0% (39.7% C2H4 54.9% C2H6 total produced compounds) after 8 h light irradiation. This work fresh insight conditions highlights significance enhanced activity unsaturated hydrocarbon product selectivity.

Язык: Английский

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Selective photocatalytic oxidation of methane by quantum-sized bismuth vanadate

Nature Sustainability, Год журнала: 2021, Номер 4(6), С. 509 - 515

Опубликована: Фев. 4, 2021

Язык: Английский

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Efficient and selective photocatalytic CH4 conversion to CH3OH with O2 by controlling overoxidation on TiO2

Nature Communications, Год журнала: 2021, Номер 12(1)

Опубликована: Авг. 2, 2021

Abstract The conversion of photocatalytic methane into methanol in high yield with selectivity remains a huge challenge due to unavoidable overoxidation. Here, the oxidation CH 4 3 OH by O 2 is carried out on Ag-decorated facet-dominated TiO . {001}-dominated shows durable 4.8 mmol g −1 h and approximately 80%, which represent much higher values than those reported recent studies are better obtained for {101}-dominated Operando Fourier transform infrared spectroscopy, electron spin resonance, nuclear magnetic resonance techniques used comprehensively clarify underlying mechanism. straightforward generation oxygen vacancies {001} photoinduced holes plays key role avoiding formation •CH •OH, main factors leading overoxidation generally formed {101} facet. results distinct intermediates reaction pathways (oxygen vacancy → Ti–O • Ti–OO–Ti Ti–(OO) pairs), thus achieving photooxidation OH.

Язык: Английский

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Binary Au–Cu Reaction Sites Decorated ZnO for Selective Methane Oxidation to C1 Oxygenates with Nearly 100% Selectivity at Room Temperature

Journal of the American Chemical Society, Год журнала: 2021, Номер 144(2), С. 740 - 750

Опубликована: Дек. 20, 2021

Direct and efficient oxidation of methane to methanol the related liquid oxygenates provides a promising pathway for sustainable chemical industry, while still remaining an ongoing challenge owing dilemma between activation overoxidation. Here, ZnO with highly dispersed dual Au Cu species as cocatalysts enables selective photocatalytic conversion one-carbon (C1) using O2 oxidant operated at ambient temperature. The optimized AuCu-ZnO photocatalyst achieves up 11225 μmol·g-1·h-1 primary products (CH3OH CH3OOH) HCHO nearly 100% selectivity, resulting in 14.1% apparent quantum yield 365 nm, much higher than previous best photocatalysts reported oxygenates. In situ EPR XPS disclose that serve photoinduced electron mediators promote •OOH, simultaneously is hole acceptor enhance H2O •OH, thus synergistically promoting charge separation transformation. This work highlights significances co-modification suitable on simultaneous regulation activity selectivity.

Язык: Английский

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Oxo dicopper anchored on carbon nitride for selective oxidation of methane

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Март 16, 2022

Selective conversion of methane (CH4) into value-added chemicals represents a grand challenge for the efficient utilization rising hydrocarbon sources. We report here dimeric copper centers supported on graphitic carbon nitride (denoted as Cu2@C3N4) advanced catalysts CH4 partial oxidation. The copper-dimer demonstrate high selectivity oxidation under both thermo- and photocatalytic reaction conditions, with hydrogen peroxide (H2O2) oxygen (O2) being used oxidizer, respectively. In particular, O2 achieves >10% conversion, >98% toward methyl oxygenates mass-specific activity 1399.3 mmol g Cu-1h-1. Mechanistic studies reveal that reactivity Cu2@C3N4 can be ascribed to symphonic mechanisms among bridging oxygen, two sites semiconducting C3N4 substrate, which do not only facilitate heterolytic scission C-H bond, but also promotes H2O2 activation in photocatalysis,

Язык: Английский

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Enabling Specific Photocatalytic Methane Oxidation by Controlling Free Radical Type

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(4), С. 2698 - 2707

Опубликована: Янв. 17, 2023

Selective CH4 oxidation to CH3OH or HCHO with O2 in H2O under mild conditions provides a desired sustainable pathway for synthesis of commodity chemicals. However, manipulating reaction selectivity while maintaining high productivity remains huge challenge due the difficulty kinetic control formation oxygenate against its overoxidation. Here, we propose highly efficient strategy, based on precise type as-formed radicals by rational design photocatalysts, achieve both and photooxidation first time. Through tuning band structure size active sites (i.e., single atoms nanoparticles) our Au/In2O3 catalyst, show alternative two important radicals, •OOH •OH, which leads distinctly different paths HCHO, respectively. This approach gives rise remarkable yield 97.62% 6.09 mmol g-1 In2O3-supported Au (Au1/In2O3) an exceptional 89.42% 5.95 nanoparticles (AuNPs/In2O3), respectively, upon photocatalytic 3 h at room temperature. work opens new avenue toward selective delicate composite photocatalysts.

Язык: Английский

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High-performance photocatalytic nonoxidative conversion of methane to ethane and hydrogen by heteroatoms-engineered TiO2

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Май 19, 2022

Abstract Nonoxidative coupling of methane (NOCM) is a highly important process to simultaneously produce multicarbons and hydrogen. Although oxide-based photocatalysis opens opportunities for NOCM at mild condition, it suffers from unsatisfying selectivity durability, due overoxidation CH 4 with lattice oxygen. Here, we propose heteroatom engineering strategy active, selective durable photocatalytic NOCM. Demonstrated by commonly used TiO 2 photocatalyst, construction Pd–O in surface reduces contribution O sites valence band, overcoming the limitations. In contrast state art, 94.3% achieved C H 6 production 0.91 mmol g –1 h along stoichiometric production, approaching level thermocatalysis relatively condition. As benchmark, apparent quantum efficiency reaches 3.05% 350 nm. Further elemental doping can elevate durability over 24 stabilizing This work provides new insights high-performance atomic engineering.

Язык: Английский

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Selective Photo-oxidation of Methane to Methanol with Oxygen over Dual-Cocatalyst-Modified Titanium Dioxide

ACS Catalysis, Год журнала: 2020, Номер 10(23), С. 14318 - 14326

Опубликована: Ноя. 23, 2020

Direct and selective oxidation of CH4 with dioxygen to methanol is a "dream reaction" in modern catalysis yet remains great challenge. Here, we report that TiO2 loaded dual cocatalysts, is, nanometals cobalt oxide (CoOx) nanoclusters, capable selectively catalyzing CH3OH at room temperature under photoexcitation using abundant inexpensive O2 as an oxidant. The best activity for the formation primary products, CH3OOH CH3OH, up 50.8 μmol 2 h 95% selectivity. Mechanistic studies elucidate superior selectivity result from synergistic effect CoOx. Nanometals enhance conversion by promoting separation photoexcited electron reduction O2. CoOx mediates mild process suppressing highly oxidative •OH radicals can further oxidize HCHO CO2, thereby preserving high toward oxygenated products. This work provides prototype designing efficient photocatalysts conditions.

Язык: Английский

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