Pressure-Dependent CO<sub>2</sub> Electroreduction to Methane over Asymmetric Cu–N<sub>2</sub> Single-Atom Sites
Haoyang Wu, Benqiang Tian, Wenhai Xu, Kovan Khasraw Abdalla, Yun Kuang, Jiazhan Li, Xiaoming Sun
Abstract
Single-atom catalysts (SACs) with unitary active sites hold great promise for realizing high selectivity toward a single product in the CO 2 electroreduction reaction (CO 2 RR). However, achieving high Faradaic efficiency (FE) of multielectron products like methane on SACs is still challenging. Herein, we report a pressure-regulating strategy that achieves 83.5 ± 4% FE for the CO 2 -to-CH 4 conversion on the asymmetric Cu–N 2 sites, representing one of the best CO 2 -to-CH 4 performances. Elevated CO 2 pressure was demonstrated as an efficient way to inhibit the hydrogen evolution reaction via promoting the competing adsorption of reactant CO 2, regardless of the nature of the active sites. Meanwhile, the asymmetric Cu–N 2 structure could endow the Cu sites with stronger electronic coupling with *CO, thus suppressing the desorption of *CO and facilitating the following hydrogenation of *CO to *CHO. This work provides a synergetic strategy of the pressure-induced reaction environment regulating and the electronic structure modulating for selective CO 2 RR toward targeted products.