Efficient and Selective CO<sub>2</sub> Reduction to Formate on Pd‐Doped Pb<sub>3</sub>(CO<sub>3</sub>)<sub>2</sub>(OH)<sub>2</sub>: Dynamic Catalyst Reconstruction and Accelerated CO<sub>2</sub> Protonation
Wenjing Huang, Yijin Wang, Jiawei Liu, Yu Wang, Daobin Liu, Jingfeng Dong, Ning Jia, Lan Yang, Chuntai Liu, Zheng Liu, Bin Liu, Qingyu Yan
Abstract
Abstract Exploring catalyst reconstruction under the electrochemical condition is critical to understanding the catalyst structure–activity relationship as well as to design effective electrocatalysts. Herein, a PbF 2 nanocluster is synthesized and its self‐reconstruction under the CO 2 reduction condition is investigated. F − leaching, CO 2 ‐saturated environment, and application of a cathodic potential induce self‐reconstruction of PbF 2 to Pb 3 (CO 3 ) 2 (OH) 2 , which effectively catalyze the CO 2 reduction to formate. The in situ formed Pb 3 (CO 3 ) 2 (OH) 2 discloses >80% formate Faradaic efficiencies (FEs) across a broad range of potentials and achieves a maximum formate FE of ≈90.1% at −1.2 V versus reversible hydrogen electrode (RHE). Kinetic studies show that the CO 2 reduction reaction (CO 2 RR) on the Pb 3 (CO 3 ) 2 (OH) 2 is rate‐limited at the CO 2 protonation step, in which proton is supplied by bicarbonate (HCO 3 − ) in the electrolyte. To improve the CO 2 RR kinetics, the Pb 3 (CO 3 ) 2 (OH) 2 is further doped with Pd (4 wt%) to enhance its HCO 3 − adsorption, which leads to accelerated protonation of CO 2 . Therefore, the Pd‐Pb 3 (CO 3 ) 2 (OH) 2 (4 wt%) reveals higher formate FEs of >90% from −0.8 to −1.2 V versus RHE and reaches a maximum formate FE of 96.5% at −1.2 V versus RHE with a current density of ≈13 mA cm −2 .