Enhancing CO<sub>2</sub> Electroreduction to Methane with a Cobalt Phthalocyanine and Zinc–Nitrogen–Carbon Tandem Catalyst
Long Lin, Tianfu Liu, Jianping Xiao, Hefei Li, Pengfei Wei, Dunfeng Gao, Bing Nan, Rui Si, Guoxiong Wang, Xinhe Bao
Abstract
Abstract Developing copper‐free catalysts for CO 2 conversion into hydrocarbons and oxygenates is highly desirable for electrochemical CO 2 reduction reaction (CO 2 RR). Herein, we report a cobalt phthalocyanine (CoPc) and zinc–nitrogen–carbon (Zn‐N‐C) tandem catalyst for CO 2 RR to CH 4 . This tandem catalyst shows a more than 100 times enhancement of the CH 4 /CO production rate ratio compared with CoPc or Zn‐N‐C alone. Density functional theory (DFT) calculations and electrochemical CO reduction reaction results suggest that CO 2 is first reduced into CO over CoPc and then CO diffuses onto Zn‐N‐C for further conversion into CH 4 over Zn‐N 4 site, decoupling complicated CO 2 RR pathway on single active site into a two‐step tandem reaction. Moreover, mechanistic analysis indicates that CoPc not only generates CO but also enhances the availability of *H over adjacent N sites in Zn‐N 4 , which is the key to achieve the high CH 4 production rate and understand the intriguing electrocatalytic behavior which is distinctive to copper‐based tandem catalysts.