Design and development of highly active and durable oxygen reduction reaction (ORR) catalyst to replace Pt- and Pt-based materials are the present challenges in fuel cell research including direct methanol fuel cells (DMFC). The methanol crossover and oxidation at cathode is another unwanted issue that reduces the efficiency of DMFC. Herein we report cobalt-doped ceria (Co-CeO2) as a promising electrocatalyst with competent ORR kinetics mainly through a four electron reduction pathway and it surpasses Pt/C by a great margin in terms of stability and methanol tolerance. The Co-CeO2 nanoparticles of diameter 4-7 nm were uniformly grown on reduced graphene oxide (rGO) by a facile single-step hydrothermal process. The as-synthesized Co-CeO2nanoparticles/rGO nanocomposites are further demonstrated as an active energy storage material in supercapacitor underlying the importance of the studied material in renewable energy industries.

http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.7b06846