<i>Operando</i> Reconstruction of Porous Carbon Supported Copper Selenide Promotes the C<sub>2</sub> Production from CO<sub>2</sub>RR
Simeng Li, Jun Yu, Shengsen Zhang, Weitao Qiu, Xing Tang, Zedong Lin, Rongming Cai, Yueping Fang, Shihe Yang, Xin Cai
Abstract
Abstract Precisely regulating surface reconstruction of copper (Cu) chalcogenides‐based catalysts to promote the multicarbon (C 2+ )selectivity of the electrochemical CO 2 reduction reaction (CO 2 RR) is hampered by the challenging control of the intractable anions and the optimal Cu δ+ reduction (0 < δ < 1). Herein, a porous carbon‐supported copper selenides electrocatalyst that can remarkably improve the C 2 ‐product yield and especially unveil the time‐revolved electrochemical CO 2 RR reconstruction process to enable the high C 2 ‐selectivity, most notably for ethanol is constructed. The Faradic efficiency (FE) of C 2 ‐products achieved is as high as ≈85.2% with a partial current density of 229.5 mA cm −2 . Operando infrared spectroscopy and density functional theory (DFT) calculations unravel that the surface Se vacancies ( V Se ) formation brings closer the neighboring Cu + atoms and activates the Cu sites, thereby rendering efficient generation of the key intermediates ( * CO and * CHO) and lowering the C–C coupling barrier for C 2 production. The appearance of metallic Cu can shorten the next‐nearest Cu 0 –Cu + distance for O atom to bridge in, leading to the preferential formation of * OC 2 H 4 towards ethanol instead of C–O bond cleavage to form ethylene. This work opens the avenue of designing suitable local atomic structures catalysts to engage the intermediates for targeted CO 2 RR products.