Abstract
The electrocatalytic reduction of CO(2) to C(2) products, driven by renewable electricity, represents a promising approach for storing intermittent renewable energy. A major challenge, however, lies in the difficulty of suppressing the competing hydrogen evolution reaction (HER), which significantly lowers the selectivity toward C(2) products and diminishes the overall efficiency of the CO(2) reduction systems. Here, we report a strategy for designing metal-based catalysts through precise regulation of the hydrothermal reaction temperature, thereby enhancing the efficiency of the conversion of CO(2) to C(2) products. The catalyst of CuO at 200 °C shows a CO(2)-to-C(2) Faradaic efficiency of 58.6% and a CO(2)-to-C(product) Faradaic efficiency of 70% at -1.4 V vs RHE. Our work provides foundational insight into the crucial role of catalyst morphology in enhancing performance in CO(2) electrolysis, facilitating the rational development of highly efficient CO(2) reduction catalysts.