In a study published in Nature Communications , a research group led by Prof. DENG Dehui, Assoc. Prof. CUI Xiaoju, and Prof. YU Liang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences has achieved highly efficient photo-driven carbonylation of methane (CH 4 ) with carbonic oxide (CO) and oxygen (O 2 ) to acetic acid (CH 3 COOH) using a nano-heterostructure catalyst.
This catalyst features Rh-Zn atomic-pair dual sites confined within a MoS 2 lattice, integrated with TiO 2 nanoparticles. This innovative catalyst enables a CH 3 COOH productivity of 152 μmol gcat. -1 h -1 , and a turnover frequency of 62 h -1 with a high selectivity of 96.5%.
The direct conversion of CH 4 to high value multi-carbon (C 2+ ) oxygenates, such as CH 3 COOH, under mild conditions presents a promising pathway for upgrading natural gas to transportable liquid chemicals.
The oxidative carbonylation of CH 4 with CO and O 2 to CH 3 COOH under mild conditions is an attractive and environmentally friendly route for CH 4 utilization. However, this process involves complex reactions, including the activation of O 2 , efficient CH 4 activation, and controllable C-C coupling. It's therefore a major challenge to achieve CH 4 , CO, and O 2 to CH 3 COOH with both high catalytic activity and selectivity for mild CH 4 conversion.
In this study, the researchers showed that the active OH species, generated from O 2 photoreduction at the Zn site by proton-coupled electron transfer, promote CH 4 dissociation to CH 3 species. These CH 3 species then easily couple with adsorbed CO at the adjacent Rh site, leading to highly selective CH 3 COOH formation.
Additionally, the dual Rh-Zn atomic-pair sites provide separate catalytic sites for C-H activation and C-C coupling, creating a synergistic effect that overcomes the typical trade-off between activity and selectivity in CH 4 carbonylation.
"Our study opens up a new horizon for the design of efficient catalysts and provides a new pathway for photo-driven CH 4 carbonylation to CH 3 COOH," said Prof. DENG.
Nature Communications
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MoS2-confined Rh-Zn atomic pair boosts photo-driven methane carbonylation to acetic acid
8-Jan-2025