Methane transformation by photocatalysis

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

Опубликована: Фев. 28, 2022

Язык: Английский

---

Synergy of Pd atoms and oxygen vacancies on In2O3 for methane conversion under visible light

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

Опубликована: Май 25, 2022

Methane (CH4) oxidation to high value chemicals under mild conditions through photocatalysis is a sustainable and appealing pathway, nevertheless confronting the critical issues regarding both conversion selectivity. Herein, visible irradiation (420 nm), synergy of palladium (Pd) atom cocatalyst oxygen vacancies (OVs) on In2O3 nanorods enables superior photocatalytic CH4 activation by O2. The optimized catalyst reaches ca. 100 μmol h-1 C1 oxygenates, with selectivity primary products (CH3OH CH3OOH) up 82.5%. Mechanism investigation elucidates that such induced dedicated function Pd single atoms boosting hole electron transfer, respectively. O2 proven be only source for CH3OH production, while H2O acts as promoter efficient ·OH production facilitates product desorption indicated DFT modeling. This work thus provides new understandings simultaneous regulation activity cocatalysts vacancies.

Язык: Английский

---

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

---

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

---

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

---

Integration of redox cocatalysts for artificial photosynthesis

Energy & Environmental Science, Год журнала: 2021, Номер 14(10), С. 5260 - 5288

Опубликована: Янв. 1, 2021

This review summarizes the design principle, emerging configurations, and photocatalytic applications of redox cocatalysts, offers insights perspectives on this topic.

Язык: Английский

---

Research progress on methane conversion coupling photocatalysis and thermocatalysis

Carbon Energy, Год журнала: 2021, Номер 3(4), С. 519 - 540

Опубликована: Июль 22, 2021

Abstract Conversion of methane into value‐added chemicals is significance for utilization and industrial demand primary chemical products. The barrier associated with the nonpolar structure high bond energy C–H (4.57 eV) makes it difficult to realize conversion activation under mild conditions. photothermal synergetic strategy by combining photon thermo provides an advanced philosophy achieve efficient conversion. In this review, we overview current pioneering studies indirect present direct way photocatalysis thermocatalysis provide a fundamental understanding activation. Finally, end review discussion on remaining challenges perspectives over single‐atom catalysts via strategy.

Язык: Английский

---

Nearly 100% selective and visible-light-driven methane conversion to formaldehyde via. single-atom Cu and Wδ+

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Май 10, 2023

Direct solar-driven methane (CH4) reforming is highly desirable but challenging, particularly to achieve a value-added product with high selectivity. Here, we identify synergistic ensemble effect of atomically dispersed copper (Cu) species and partially reduced tungsten (Wδ+), stabilised over an oxygen-vacancy-rich WO3, which enables exceptional photocatalytic CH4 conversion formaldehyde (HCHO) under visible light, leading nearly 100% selectivity, very yield 4979.0 μmol·g-1 within 2 h, the normalised mass activity 8.5 × 106 μmol·g-1Cu·h-1 HCHO at ambient temperature. In-situ EPR XPS analyses indicate that Cu serve as electron acceptor, promoting photo-induced transfer from conduction band O2, generating reactive •OOH radicals. In parallel, adjacent Wδ+ act hole acceptor preferred adsorption activation site H2O produce hydroxyl radicals (•OH), thus activate methyl (•CH3). The synergy dual active sites boosts overall efficiency selectivity process.

Язык: Английский

---

Molecular oxygen enhances H2O2 utilization for the photocatalytic conversion of methane to liquid-phase oxygenates

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

Опубликована: Ноя. 5, 2022

H2O2 is widely used as an oxidant for photocatalytic methane conversion to value-added chemicals over oxide-based photocatalysts under mild conditions, but suffers from low utilization efficiencies. Herein, we report that O2 efficient molecular additive enhance the efficiency of by suppressing adsorption on oxides and consequent photogenerated holes-mediated dissociation into O2. In anatase TiO2 nanocrystals predominantly enclosed {001} facets (denoted TiO2{001})-C3N4 composite photocatalyst at room temperature ambient pressure, significantly enhances up 93.3%, giving formic acid liquid-phase oxygenates selectivities respectively 69.8% 97% a yield 486 μmolHCOOH·gcatalyst-1·h-1. Efficient charge separation within TiO2{001}-C3N4 heterojunctions, activation CH4 ·CH3 radicals TiO2{001} electrons-mediated ·OOH C3N4, preferential dissociative methanol are responsible active selective photocatalyst.

Язык: Английский

---

Asymmetrically coordinated cobalt single atom on carbon nitride for highly selective photocatalytic oxidation of CH4 to CH3OH

Chem, Год журнала: 2023, Номер 9(4), С. 1017 - 1035

Опубликована: Март 13, 2023

Язык: Английский

---