Co7Se8 Nanostructures as Catalysts for Oxygen Reduction Reaction with High Methanol Tolerance

Abstract

Co7Se8 nanostructures electrodeposited on glassy carbon (GC) electrodes show high efficiency for oxygen reduction reaction (ORR) with high methanol tolerance as compared to Pt electrocatalysts. In the presence of methanol, the onset potential for the ORR at Pt/GC is shifted from 0.931 V (vs reversible hydrogen electrode (RHE)) to 0.801 V (vs RHE), whereas it remains the same (0.811 V vs RHE) at Co7Se8/GC in the presence and absence of methanol in 0.5 M H2SO4 solution. The Co7Se8/GC electrodes also showed high cyclability in the presence of methanol, with no degradation of catalytic performance. It is also noteworthy that the Co7Se8/GC exhibited exclusively a four-electron reduction pathway for ORR and very low H2O2 yield in acidic electrolyte. The admirable performance of Co7Se8/GC catalyst along with its cost-effective nature holds great potential for application in direct methanol fuel cells.