A Co3O4-CDots-C3N4 Three Component Electrocatalyst Design Concept for Efficient and Tunable CO2 Reduction to Syngas
Sijie Guo1, Siqi Zhao1, Xiuqin Wu1, Hao Li1, Yunjie Zhou1, Cheng Zhu1, Nianjun Yang2, Xin Jiang2, Jin Gao1, Liang Bai1, Yang Liu1, Yeshayahu Lifshitz1,3, Shuit-Tong Lee1& Zhenhui Kang1
1Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials(FUNSOM), Soochow University, 199 Ren’ai Road, Suzhou, 215123 Jiangsu, China.
2Institute of Materials Engineering, University of Siegen, 57076 Siegen, Germany.
3Department of Materials Science and Engineering, Technion, Israel Institute of Technology, Haifa 3200003, Israel.
Syngas, a CO and H2 mixture mostly generated from non-renewable fossil fuels, is an essential feedstock for production of liquid fuels. Electrochemical reduction of CO2 and H+/H2O is an alternative renewable route to produce syngas. Here we introduce the concept of coupling a hydrogen evolution reaction(HER) catalyst with a CDots/C3N4 composite (a CO2 reduction catalyst) to achieve a cheap, stable, selective, and efficient route for tunable syngas production. Co3O4, MoS2, Au, and Pt serve as the HER component. The Co3O4-CDots-C3N4 electrocatalyst is found to be the most efficient among the combinations studied. The H2/CO ratio of the produced syngas is tunable from 0.07:1 to 4:1 by controlling the potential. This catalyst is highly stable for syngas generation (over 100h) with no other products besides CO and H2. Insight into the mechanisms balancing between CO2 reduction and H2 evolution when applying the HER-CDots-C3N4 catalyst concept is provided.