Highly Selective\nElectroreduction of Carbon Dioxide\nUsing Defect-Driven Catalysis

The production of methanol from the electrochemical reduction\nof\nCO<sub>2</sub> is a promising method of mitigating climate change\nwhile simultaneously producing a useful liquid fuel. In this study,\nwe design self-assembled monolayers (SAMs) of thiols on metal and\nmetal oxide electrodes that operate via cooperative catalysis between\nthe thiolated surface sites and exposed electrode defect sites. This\ndefect-driven mechanism enables the fabrication of SAM-modified ZnO\nelectrodes that yield methanol with an extraordinarily high Faradaic\nefficiency of up to 92%. To understand the origin of this high selectivity,\nwe study the effect of the chain length of the alkanethiols, different\ntail functional groups, and applied voltages on catalyst performance.\nThese results combined with density functional theory calculations\ngive a detailed atomic-level understanding of catalyst operation.\nFurthermore, the SAM linkage tolerates CO<sub>2</sub> reduction conditions,\nand the catalyst’s excellent selectivity for methanol remains\nhigh after 10 h of continuous conversion. Taken together, these findings\nwith SAM-based electrodes convey a new and facile design strategy\nfor the creation of highly selective CO<sub>2</sub> reduction electrocatalysts.