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Electroreduction of carbon dioxide into value-added fuels or chemicals using renewable energy helps to effectively reduce carbon dioxide emission and alleviate the greenhouse effect while storing intermittent energies. Due to the existing infrastructure of global natural gas utilization and distribution, methane produced in such a green route attracts wide interests. However, limited success has been witnessed in the practical application of catalysts imparting satisfactory methane activity and selectivity. Herein, we report the fabrication of an atomically dispersed Co−Cu alloy through the reconstruction of trace-Co doped Cu metal-organic framework. This catalyst exhibits a methane Faradaic efficiency of 60% ± 1% with the corresponding partial current density of 303 ± 5 mA·cm−2. Operando X-ray adsorption spectroscopy and attenuated-total-reflection surface enhanced infrared spectroscopy unravel that the introduction of atomically dispersed Co in Cu favors *CO protonation via enhancing surface water activation, and suppresses C−C coupling by reducing *CO coverage, thereby leading to high methane selectivity. [ABSTRACT FROM AUTHOR]

Direct implementation of metal-organic frameworks as the catalyst for CO2 electroreduction has been challenging due to issues such as poor conductivity, stability, and limited > 2e− products. In this study, Au nanoneedles are impregnated into a cupric porphyrin-based metal-organic framework by exploiting ligand carboxylates as the Au3+ -reducing agent, simultaneously cleaving the ligand-node linkage. Surprisingly, despite the lack of a coherent structure, the Au-inserted framework affords a superb ethylene selectivity up to 52.5% in Faradaic efficiency, ranking among the best for metal-organic frameworks reported in the literature. Through operando X-ray, infrared spectroscopies and density functional theory calculations, the enhanced ethylene selectivity is attributed to Au-activated nitrogen motifs in coordination with the Cu centers for C-C coupling at the metalloporphyrin sites. Furthermore, the Au-inserted catalyst demonstrates both improved structural and catalytic stability, ascribed to the altered charge conduction path that bypasses the incoherent framework. This study underlines the modulation of reticular metalloporphyrin structure by metal impregnation for steering the CO2 reduction reaction pathway. Metal-organic frameworks are promising catalysts for CO2 electroreduction, yet limited by their poor conductivity and stability. Here, Au nanoneedles are inserted into the metalloporphyrin framework to activate C-C coupling and stabilize the structure for much enhanced ethylene production. [ABSTRACT FROM AUTHOR]

Direct implementation of metal-organic frameworks as the catalyst for CO2 electroreduction has been challenging due to issues such as poor conductivity, stability, and limited > 2e− products. In this study, Au nanoneedles are impregnated into a cupric porphyrin-based metal-organic framework by exploiting ligand carboxylates as the Au3+ -reducing agent, simultaneously cleaving the ligand-node linkage. Surprisingly, despite the lack of a coherent structure, the Au-inserted framework affords a superb ethylene selectivity up to 52.5% in Faradaic efficiency, ranking among the best for metal-organic frameworks reported in the literature. Through operando X-ray, infrared spectroscopies and density functional theory calculations, the enhanced ethylene selectivity is attributed to Au-activated nitrogen motifs in coordination with the Cu centers for C-C coupling at the metalloporphyrin sites. Furthermore, the Au-inserted catalyst demonstrates both improved structural and catalytic stability, ascribed to the altered charge conduction path that bypasses the incoherent framework. This study underlines the modulation of reticular metalloporphyrin structure by metal impregnation for steering the CO2 reduction reaction pathway. Metal-organic frameworks are promising catalysts for CO2 electroreduction, yet limited by their poor conductivity and stability. Here, Au nanoneedles are inserted into the metalloporphyrin framework to activate C-C coupling and stabilize the structure for much enhanced ethylene production. [ABSTRACT FROM AUTHOR]