Structural construction of Bi-anchored honeycomb N-doped porous carbon catalyst for efficient CO2 conversion

Electrocatalytic CO2 reduction reaction (CO2RR) technology has attracted extensive attention owing to mild reaction conditions, high energy conversion efficiency, and facile adaptability. However, it remains a great challenge for the lack of highly active catalysts and the selectivity of reduction products. Herein, we successfully fabricated the Bi nanoparticles diffused in nitrogen-doped carbon frame catalysts (Bi@NCFs) by an in-situ pyrolysis process. The electrocatalytic test results demonstrate that the Faradaic efficiency of formate (FEHCOOH) of Bi@NCFs catalyst is higher than 79% in the potential range of −0.8~-1.3 V vs. RHE, of which FEHCOOH is as high as 95.70% at −1.0 V vs. RHE. After 48 h stability test, the FEHCOOH still preserves over 81.3%, indicating excellent durability and stability of the catalyst in H-cell. The synergistic effect between the honeycomb-like porous carbon framework and Bi NPs enhance the electrocatalytic activity of the catalyst; on the other hand, nano-scale Bi particles exist on the surface and inside of the porous carbon framework, increasing the active sites for CO2RR. Even under high current in the flow cell, the catalyst exhibits high formic acid selectivity and DFT calculation proves the superiority of formic acid generation. This work provides insights into synthesizing N-doped porous carbon framework supported nano-metal catalysts for CO2RR.