High efficiency and selectivity from synergy: Bi nanoparticles embedded in nitrogen doped porous carbon for electrochemical reduction of CO2 to formate

Electrochemical reduction of CO2 (ECR) into formate is an efficient and environmentally friendly approach contributing to carbon-neutral cycle. However, conventional catalysts for ECR usually suffer from low product selectivity, inferior activity and poor durability. Herein, we highlight Bi nanoparticles embedded in nitrogen doped porous carbon (Bi@NPC) as a promising integrated catalyst for ECR. This catalyst demonstrates a remarkable formate faradaic efficiency of 92.0%, and more encouragingly, a high formate current density of 14.4 mA cm(-2) at a low potential of -1.5 V (vs SCE) in 0.1 M KHCO3 solution, which is significantly superior to the individual Bi nanoparticles (Bi-NP). Besides, the Bi@NPC catalyst exhibits a robust durability for 20 h operation. The advanced electrocatalytic performance of the Bi@NPC catalyst is likely attributed to the ensemble effect of Bi nanoparticles and NPC matrix. This attractive route discloses a broad prospect for the development of a promising integrated catalyst for ECR. (C) 2019 Elsevier Ltd. All rights reserved.