Borocarbonitrides As Metal-Free Electrocatalysts for the Electrochemical Reduction of CO₂

Electrochemical reduction of CO2 to produce value-added fuels is an effective strategy for capturing and utilizing atmospheric CO2. The development of an electrocatalyst for efficient and selective reduction of CO2 is highly desirable. However, most of the research focuses on metal-based catalysts, which suffer from drawbacks such as high cost, limited resource availability, and competing hydrogen evolution. Herein, we study the electrochemical reduction of CO2 on metal-free borocarbonitride (BxCyNz) catalysts in an aqueous electrolyte. BC1.2N0.8 catalyst exhibits high selectivity for CO, reaching a CO faradaic efficiency of 98% at −0.45 V (vs RHE). Thus, we have tuned the composition of BxCyNz to study the effects of incorporating B and N in a carbon lattice. This work provides insights into the effects of codoping heteroatoms in a carbon lattice on the surface area, CO2 uptake, and electrochemical reduction of CO2. A linear correlation was observed between FECO and N content, specifically pyridinic N content, shedding light on the active site for the electrochemical reduction of CO2.