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.