Tandem catalysis on adjacent active motifs of copper grain boundary for efficient CO_(2) electroreduction toward C2 products

摘要

Copper (Cu) is a special electrocatalyst for CO_(2) reduction reaction (CO_(2)RR) to multi-carbon products.Experimentally introducing grain boundaries (GBs) into Cu-based catalysts is an efficient strategy to improve the selectivity of C^(2+) products.However,it is still elusive for the C^(2+) product generation on Cu GBs due to the complex active sites.In this work,we found that the tandem catalysis pathway on adjacent active motifs of Cu GB is responsible for the enhanced activity for C^(2+)production by first principles calculations.By electronic structure analysis shows,the d-band center of GB site is close to the Fermi level than Cu(100) facet,the Cu atomic sites at grain boundary have shorter bond length and stronger bonding with*CO,which can enhance the adsorption of*CO at GB sites.Moreover,CO_(2)protonation is more favorable on the region Ⅲ motif (0.84 e V) than at Cu(100) site (1.35 e V).Meanwhile,the region Ⅱ motif also facilitate the C–C coupling (0.72 e V) compared to the Cu(100) motif (1.09 e V).Therefore,the region Ⅲ and Ⅱ motifs form a tandem catalysis pathway,which promotes the C^(2+)selectivity on Cu GBs.This work provides new insights into CO_(2)RR process.