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

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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 quantum efficiency of hydrogen production from methanol aqueous solution with PtCu–TiO2 photocatalysts

Nature Materials, Год журнала: 2023, Номер 22(5), С. 619 - 626

Опубликована: Апрель 10, 2023

Язык: Английский

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Room-Temperature Photooxidation of CH₄ to CH₃OH with Nearly 100% Selectivity over Hetero-ZnO/Fe₂O₃ Porous Nanosheets

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(27), С. 12357 - 12366

Опубликована: Июнь 28, 2022

The huge challenge for CH4 photooxidation into CH3OH lies in the activation of inert C-H bond and inhibition overoxidation. Herein, we design two-dimensional in-plane Z-scheme heterostructures composed two different metal oxides, with efforts to polarize symmetrical molecules strengthen O-H CH3OH. As a prototype, first fabricate ZnO/Fe2O3 porous nanosheets, where high-resolution transmission electron microscopy situ X-ray photoelectron spectroscopy affirm their heterostructure. In Fourier transform infrared spectra paramagnetic resonance demonstrate higher amount ·CH3 radicals relative pristine ZnO which density functional theory calculations validate that high local charge accumulation on Fe sites lowers adsorption energy from 0.14 0.06 eV. Moreover, charge-accumulated polarity through transferring electrons O atoms, confirmed by increased barrier 0.30 2.63 eV *CH3O formation, inhibits homolytic cleavage thus suppresses Accordingly, selectivity over nanosheets reaches up nearly 100% an activity 178.3 μmol-1 gcat-1, outperforming previously reported photocatalysts without adding any oxidants under room temperature ambient pressure.

Язык: Английский

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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

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Direct Photocatalytic Synthesis of Acetic Acid from Methane and CO at Ambient Temperature Using Water as Oxidant

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(2), С. 1185 - 1193

Опубликована: Янв. 2, 2023

Direct functionalization of methane selectively to value-added chemicals is still one the main challenges in modern science. Acetic acid an important industrial chemical produced nowadays by expensive and environmentally unfriendly carbonylation methanol using homogeneous catalysts. Here, we report a new photocatalytic reaction route synthesize acetic from CH4 CO at room temperature water as sole external oxygen source. The optimized photocatalyst consists TiO2 support ammonium phosphotungstic polyoxometalate (NPW) clusters anchored with isolated Pt single atoms (Pt1). It enables stable synthesis 5.7 mmol·L–1 solution 60 h selectivity over 90% 66% on liquid-phase carbon basis, respectively, production 99 mol per Pt. Combined isotopic situ spectroscopy investigation suggests that proceeds via oxidative Pt1 sites, activation facilitated water-derived hydroxyl radicals.

Язык: Английский

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Adaptable graphitic C6N6-based copper single-atom catalyst for intelligent biosensing

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

Опубликована: Май 15, 2023

Self-adaptability is highly envisioned for artificial devices such as robots with chemical noses. For this goal, seeking catalysts multiple and modulable reaction pathways promising but generally hampered by inconsistent conditions negative internal interferences. Herein, we report an adaptable graphitic C6N6-based copper single-atom catalyst. It drives the basic oxidation of peroxidase substrates a bound copper-oxo pathway, undertakes second gain triggered light via free hydroxyl radical pathway. Such multiformity reactive oxygen-related intermediates same makes capable to be same. Moreover, unique topological structure CuSAC6N6 along specialized donor-π-acceptor linker promotes intramolecular charge separation migration, thus inhibiting interferences above two pathways. As result, sound activity superb up 3.6 times under household lights are observed, superior that controls, including peroxidase-like catalysts, photocatalysts, or their mixtures. further applied glucose biosensor, which can intelligently switch sensitivity linear detection range in vitro.

Язык: Английский

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Light-driven flow synthesis of acetic acid from methane with chemical looping

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

Опубликована: Май 26, 2023

Oxidative carbonylation of methane is an appealing approach to the synthesis acetic acid but limited by demand for additional reagents. Here, we report a direct CH3COOH solely from CH4 via photochemical conversion without This made possible through construction PdO/Pd-WO3 heterointerface nanocomposite containing active sites activation and C-C coupling. In situ characterizations reveal that dissociated into methyl groups on Pd while oxygen PdO responsible carbonyl formation. The cascade reaction between generates acetyl precursor which subsequently converted CH3COOH. Remarkably, production rate 1.5 mmol gPd-1 h-1 selectivity 91.6% toward achieved in flow reactor. work provides insights intermediate control material design, opens avenue oxygenates.

Язык: Английский

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Recent trends, current challenges and future prospects for syngas-free methane partial oxidation

Nature Catalysis, Год журнала: 2023, Номер 6(9), С. 748 - 762

Опубликована: Сен. 21, 2023

Язык: Английский

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Photocatalytic ethylene production by oxidative dehydrogenation of ethane with dioxygen on ZnO-supported PdZn intermetallic nanoparticles

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Янв. 26, 2024

Abstract The selective oxidative dehydrogenation of ethane (ODHE) is attracting increasing attention as a method for ethylene production. Typically, thermocatalysts operating at high temperatures are needed C–H activation in ethane. In this study, we describe low temperature ( < 140 °C) photocatalytic route ODHE, using O 2 the oxidant. A photocatalyst containing PdZn intermetallic nanoparticles supported on ZnO prepared, affording an production rate 46.4 mmol g –1 h with 92.6% selectivity under 365 nm irradiation. When employ simulated shale gas feed, ODHE system achieves nearly 20% conversion while maintaining about 87%. robust interface between and support plays crucial role through photo-assisted Mars-van Krevelen mechanism, followed by rapid lattice oxygen replenishment to complete reaction cycle. Our findings demonstrate that promising alkane-to-alkene conversions mild conditions.

Язык: Английский

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