Revealing the Kinetic Balance between Proton‐Feeding and Hydrogenation in CO<sub>2</sub> Electroreduction
Sha Bai, Ling Tan, Chenjun Ning, Guihao Liu, Zhaohui Wu, Tianyang Shen, Lirong Zheng, Yu‐Fei Song
Abstract
Abstract Electrocatalytic reduction of CO 2 to high‐value‐added chemicals provides a feasible path for global carbon balance. Herein, the fabrication of Ni NP x @Ni SA y ‐NG ( x,y = 1, 2, 3; NG = nitrogen‐doped graphite) is reported, in which Ni single atom sites (Ni SA ) and Ni nanoparticles (Ni NP ) coexist. These Ni NP x @Ni SA y ‐NG presented a volcano‐like trend for maximum CO Faradaic efficiency (FE CO ) with the highest point at Ni NP2 @Ni SA2 ‐NG in CO 2 RR. Ni NP2 @Ni SA2 ‐NG exhibited ≈98% of maximum FE CO and a large current density of −264 mA cm −2 at −0.98 V (vs. RHE) in the flow cell. In situ experiment and density functional theory (DFT) calculations confirmed that the proper content of Ni SA and Ni NP balanced kinetic between proton‐feeding and CO 2 hydrogenation. The Ni NP in Ni NP2 @Ni SA2 ‐NG promoted the formation of H* and reduced the energy barrier of *CO 2 hydrogenation to *COOH, and CO desorption can be efficiently facilitated by Ni SA sites, thereby resulting in enhanced CO 2 RR performance.