A Cu2B2 monolayer with planar hypercoordinate motifs: an efficient catalyst for CO electroreduction to ethanol

Abstract

Sustainable production of high-value carbon-based fuels and chemicals through electrochemical CO reduction (COR) under mild conditions is a promising alternative to the traditional Fischer–Tropsch process that requires high energy input and large-scale reactors. However, the COR process suffers from the low activity and poor selectivity of the currently employed electrocatalysts, greatly hampering its large-scale application. Herein, by means of comprehensive swarm-intelligence structure search and first-principles computations, we identify an ideal electrocatalyst for COR, i.e., a metallic Cu₂B₂ monolayer with planar heptacoordinate copper and planar pentacoordinate boron. Our results reveal that the predicted Cu₂B₂ monolayer exhibits superior thermal and dynamic stability and holds promise for experimental realization. More importantly, this catalyst could effectively reduce CO to ethanol through the “carbene” mechanism with a low limiting potential (−0.59 V) and a small barrier for C–C coupling (0.41 eV). Our work is the first report on the as-designed electrocatalyst with planar hypercoordinate motifs for CO reduction to C₂ products, which not only widens the potential application of hypercoordinate 2D materials, but also opens up a new and promising avenue for converting abundant industrial CO to value-added ethanol.