Carbene bridging Ag-Cu sites for enhanced *CO pooling and C-C coupling in CO2 reduction

The electrocatalytic carbon dioxide reduction reaction (CO₂RR) offers a sustainable route to convert CO₂ into high-value chemicals and fuels using renewable electricity. Among various products, multi-carbon (C₂₊) chemicals like ethylene and ethanol are highly sought after due to their high energy densities and commercial values. Cu-based catalysts are widely studied for C₂₊ production owing to their unique ability to facilitate C-C coupling.However, achieving high selectivity for C₂₊ products remains a major challenge because of the low coverage of critical *CO intermediates and the sluggish kinetics of the C-C coupling process.

Recently, a research team led by Prof. Jianmei Lu, Prof. Qingfeng Xu, and Prof. Youyong Li from Soochow University developed an efficient strategy involving carbene dual-function bridging of Ag-Cu sites to overcome these bottlenecks. By integrating experimental observations with theoretical simulations, the team demonstrated how surface modification can effectively strengthentandem synergistic effects to boost catalytic performance.Their findings were published in the Chinese Journal of Catalysis (DOI: 10.1016/S1872-2067(25)64888-1).

Carbenes were self-assembled onto the Ag-Cu₂O surface via the in-situ deprotonation of imidazolium cations by generated OH^-ions. The synthesized Ag-Cu₂O-carbene catalyst exhibited a remarkable C₂₊ Faradaic efficiency of 80.3% at a current density of 400 mA cm^-2, significantly outperforming both pristine Cu₂O and unmodified Ag-Cu₂O catalysts, identifying that the introduction of carbene species is a decisive factor in boosting the selectivity for high-value C₂₊ products.

The improved performance is attributed to the enhanced tandem synergy induced by the carbene dual-function bridging of Ag-Cu sites. In-situ spectroscopic experiments and density functional theorycalculations collectively uncovered the underlying mechanism. Carbene modification enhances the "desorption-re-adsorption" tandem spillover of *CO intermediates from Ag sites to Cu sites, thereby increasing the surface coverage of *CO on the Cu species. Furthermore, the carbene modulates the electronic structure of Cu, effectively lowering the energy barrier for *CO hydrogenation to facilitate the formation of key intermediates such as *CHO and *COCHO. This dual-functionality ensures the smooth progression of C-C coupling reactions and achieves high selectivity for C₂₊ products. Surface modification to enhance the synergistic effect of multiple catalytic sites representing a promising approach for promoting efficient CO₂ electroreduction.

About the journal

Chinese Journal of Catalysisis co-sponsored by Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Chinese Chemical Society, and it is currently published by Elsevier group. This monthly journal publishes in English timely contributions of original and rigorously reviewed manuscripts covering all areas of catalysis. The journal publishes Reviews, Accounts, Communications, Articles, Highlights, Perspectives, and Viewpoints of highly scientific values that help understanding and defining of new concepts in both fundamental issues and practical applications of catalysis.Chinese Journal of Catalysisranks among the top six journals in Applied Chemistry with a current SCI impact factor of 17.7.

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