Boron-doped electrocatalysts derived from carbon dioxide

Abstract

This work addresses the derivation of active electrocatalysts using carbon dioxide (CO₂) as a carbon source. CO₂ is converted to boron-doped porous carbon (B-PC) with sodium borohydride as a reduction agent at ambient pressure and 500 °C. Further activation of the BPC using the thermal treatment in the presence of NaBH₄ greatly enhances its catalytic activity for oxygen reduction reaction (ORR). The treated B-PC has ORR activity comparable to a Pt-activated carbon (Pt-AC) catalyst but it shows better ORR selectivity. The improvement of electrocatalytic performance is not originated from the carbon morphology change but comes from the change of surface boron bonds with carbon atoms and the widened π state. The synthesis of B-PC from CO₂ under mild conditions and the application of the derived B-PC to the fuel cell electrode might be one feasible way of numerous sustainable CO₂ utilization practices.