Trace copper and bi-nonmetallic (N/S) modified ketjenblack (KB) as advanced electrocatalysts for oxygen reduction reactions

Abstract

The sluggish oxygen reduction reaction (ORR) has been one of the most majority bottlenecks of fuel cells and metal-air batteries. It is extremely desirable but challenging to explore low cost, highly active, stable catalysts toward ORR to replace commercial Pt/C catalysts. Herein, a novel hybrid system consisting of trace copper and bi-nonmetallic (N/S) modified the commercial ketjenblack (KB) carbon (Cu–NS–C) has been successfully fabricated by a pyrolysis of Cu–MOF/KB and thiourea to transform crystalline Cu/Cu₂O nanoparticles into copper sulfide nanoparticles and the subsequent acid leaching. The optimized Cu–NS–C delivers a half-wave potential of 0.81 V versus RHE and a limiting-current density of 5.0 mA cm⁻², which is next to those of commercial 20 wt% Pt/C catalyst. Furthermore, this catalyst demonstrates much better durability and methanol tolerance than Pt/C catalyst.