A covalency-aided electrochemical mechanism for CO 2 reduction: the synergistic effect of copper and boron dual active sites drives the formation of a high-efficiency ethanol product.

Electrocatalytic carbon dioxide (CO 2 ) conversion into high-value multi-carbon products is of great significance for CO 2 utilization, but the chemical inertness, low yields, and poor product selectivity hinder the application prospects of the electrocatalytic conversion methods. In this work, a covalency-aided electrochemical mechanism for CO 2 reduction is proposed for the first time by embedding the nonmetallic element boron (B) on copper surfaces, in which p-block dopants have a significant impact on modifying the adsorbent intermediates and improving the catalytic activity. Herein, B atoms not only provide empty and occupied orbitals to adsorb and activate CO, but also afford a large amount of charge to stabilize the C 2 intermediates. In addition, B atoms can also adjust the oxidation state of nearby copper (namely, Cu + ), and the synergistic Cu + and B dual active sites act as O* adsorption and C* adsorption sites, respectively, leading to strong adsorption and activation of CO 2 . First-principles calculations reveal that CO 2 can be reduced into C 2 H 5 OH with an ultralow potential of -0.26 V. Overall, this study provides new insights into CO 2 reduction, which offers a promising way for achieving an efficient ethanol product.