Highly Selective Acidic CO<sub>2</sub> Electroreduction with Large Current on Polypyrrole‐Modified Ag Catalyst by Local Microenvironment Modulation
Zhenhui Wang, Weizhou Wang, Qin Yang, Yanling Geng, Yunmei Du, Kang Liu, Zexing Wu, Jianping Lai, Bin Li, Hongdong Li, Gengfeng Zheng, Lei Wang
Abstract
Abstract Electrocatalytic carbon dioxide reduction (CO 2 RR) holds great promise for carbon capture and utilization. In acidic media, CO 2 RR enables efficient CO 2 conversion, but with low selectivity due to the competitive hydrogen evolution reaction (HER) and catalyst corrosion. Herein, conductive polymer polypyrrole (PPy) coated Ag nanoparticles (NPs) catalysts (Ag@PPy) with different thicknesses are designed and synthesized, which could create a hydrophobic environment that reduces the accessibility of H 2 O to the Ag NPs thereby inhibiting HER. The coating of the PPy layer also protects the catalysts from corrosion and improves the stability of the system. Among them, Ag@PPy‐2 with the appropriate thickness showed up to 91.7% for the electrocatalytic reduction of CO 2 to CO and high durability in acidic electrolyte at −300 mA cm −2 . Density functional theory (DFT) calculation shows that Ag nanoparticles coated with PPy not only inhibit the competitive HER, but also reduce the CO 2 RR energy barrier, and improve the efficiency of CO 2 to CO. This study may provide some new ideas for the design of advanced selective electrocatalytic CO 2 reduction catalysts by local microenvironmental engineering.