Rationally tailoring electron and proton transfer over pyridinic N by electron-deficient BC3 for promoting CO2 electroreduction kinetics on porous graphene

Abstract

Coupled electron-proton transfer dominates the activity and selectivity of electrochemical CO2 reduction (CO2RR), still the concern on proton-feeding is far from satisfied especially in nitrogen-doped carbonaceous catalysts. Here, we report that pyridinic N cooperated with electron-donating BC3 provides with strengthened Lewis basicity for favorably electrophilic attack of CO2 and beneficial electron transfer, while implanted BC3 trigger water activation for availably proton-feeding, conducting to superior CO production rate on two-step synthesized B and N co-doped porous graphene (tBNPG) over single N-doped reference. Inspired by such cognition, oxygen-containing groups applauded by their charge induced effect, were further decorated on tBNPG but elevating the competitive H2 evolution (HER). Mechanistic studies illustrate that lateral oxygen functionalities, especially –COOH, deliver BC3 sites much lower limiting potentials for H2O transition to *H, determining whose fate branches to HER versus CO2RR. The atomic-level insight paves the cornerstone for the catalysts design of proton-involved electrochemical reactions.