Graphene-Supported Single-Atom Ni as High-Performance Catalyst for Direct Methane-to-Methanol Conversion

The Journal of Physical Chemistry C, Год журнала: 2023, Номер 127(39), С. 19527 - 19535

Опубликована: Сен. 27, 2023

Inspired by the excellent performance of NiO+ in converting CH4 to CH3OH gas phase and efficiency single-atom catalysts, we constructed a Ni–O active site on single-vacant (SV) graphene using O3/N2O as oxidant. Quantum chemistry calculations predict Ni/SV-graphene be potential catalyst for CH4-to-CH3OH conversion, outperforming Pd or Pt/SV-graphene both activity selectivity. The radical pathway is favored, C–H bond activation rate-determining step, during which an electron transferred from O-atom OM/SV-graphene pushes σM–O orbital σM–O*. ONi/SV-graphene has smaller σM–O* energy gap than its Pd/Pt counterparts, thus more readily transferring activate bond, making it best catalyst. In addition, capable recycling avoiding overoxidizing methanol. This study provides theoretical insights into developing efficient noble-metal-free catalysts direct conversion.

Язык: Английский

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Site Isolated Rh(II) Metalloradicals Catalyze Olefin Hydrosilylation

Опубликована: Авг. 14, 2023

Rh(II) porphyrin complexes display pronounced metal-centered radical character and the ability to activate small molecules under mild conditions, but catalysis with porphyrins is extremely rare. In addition facile dimerization, readily engage in kinetically thermodynamically reactions involving two centers generate stable Rh(III)-X intermediates that obstruct turnover thermal catalysis. Here we report site isolation of metalloradicals a MOF host, which not only protects against also allows them participate Access PCN-224 or PCN-222 linkers are fully metalated by absence any accom-panying Rh(0) nanoparticles was achieved via first direct synthesis linker containing transition-metal alkyl moiety, followed Rh(III)–C bond photolysis.

Язык: Английский

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Solar-Driven Reforming of Methane and Nitrogen to Methanol and Ammonium on Iron-Modified Zeolite under Ambient Conditions in Water

Inorganic Chemistry, Год журнала: 2023, Номер 62(36), С. 14804 - 14814

Опубликована: Авг. 29, 2023

Artificial photosynthesis from selective methane oxidation or nitrogen reduction to value-added chemicals provides a promising pathway for the sustainable chemical industry, while still remaining great challenge due extreme difficulty in C-H and N≡N bond cleavage under ambient conditions. Catalysts that can cocatalyze these two reactions simultaneously are rarely reported. Here, Fe-ZSM-5 with highly dispersed extra-framework Fe-oxo species enables efficient photocatalytic conversion of coproduce methanol ammonia using H2O as redox reagent The optimized photocatalyst achieves up 0.88 mol/molFe·h products 97% selectivity. Meanwhile, productivity is 0.61 mol/molFe·h. In situ EPR DRIFT studies disclose water serves provide hydroxyl radicals protons hydrogenation. Quantum calculations revealed play significant role coactivation molecules, which lowers energy barriers rate-determining steps generation.

Язык: Английский

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Molecular dynamics simulations of liquid gallium alloy Ga–X (X = Pt, Pd, Rh) via machine learning potentials

Inorganic Chemistry Frontiers, Год журнала: 2024, Номер 11(5), С. 1573 - 1582

Опубликована: Янв. 1, 2024

Machine learning-based moment tensor potential (MTP) was developed to simulate the coordination and diffusion properties of transition metal atoms in liquid gallium.

Язык: Английский

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Research progress in low-temperature catalytic direct conversion of methane to C<sub>2</sub> value-added chemicals

Scientia Sinica Chimica, Год журнала: 2024, Номер 54(3), С. 353 - 369

Опубликована: Фев. 4, 2024

Methane, which is abundant and affordable, not only a high-quality fossil fuel, but also new material for synthesizing high-value chemicals. Due to its inertness, the direct conversion of methane requires high activation energy usually harsh reaction conditions or strong oxidizing agents. Directly converting into valuable under mild promising technique, can reduce thermodynamic barrier in methane, avoid common problems peroxides catalyst deactivation, it still huge challenge. In this review, research progress anaerobic systems aerobic catalyzed C₂ value-added chemicals reviewed. The construction catalysts elaborated discussed detail from aspects active centers mechanism. Finally, we take look at challenges facing area propose potential solutions.

Язык: Английский

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