Key Words:ELECTROREDUCTION; COPPER

Abstract:Cu-based heterostructured composites are a class of important CO2 electrochemical reduction (CO2ER) catalysts, yet usually undergo structure reconstruction under working conditions. To reveal the underlying evolution of catalyst structures and discover their influence on reaction selectivity are fundamentally crucial yet challengeable. Herein, we systematically investigate the evolution of a heterostructured Al(OH)3/CuS catalyst with potentials and thereby the dependence of product selectivity for CO2ER on the in-situ evolved structures. It is discovered that CuS is partially stabilized at -0.8 VRHE with high selectivity for HCOOH (37 %). At -1.2 VRHE, the heterostructured Al(OH)3/CuS is completely evolved into Al,S-incorporated Cu2O, which exhibits a maximal FEC2+ of 54 %. In-situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATRSEIRAS) reveals that *OCHO is preferentially formed at -0.8 VRHE while *CHO and *COCHO are the predominant intermediates at -1.2 VRHE, leading to formation of C2+ products. This work provides new insights on potential-dependent structure evolution and tunable C1/C2+ selectivity of CO2ER, which is expected to provide basis for catalyst design to boost C2+ production.

Volume:69

Issue:

Translation or Not:no