Sulfur-doped porous graphene frameworks as an efficient metal-free electrocatalyst for oxygen reduction reaction

We developed sulfur-doped porous graphene frameworks as a highly efficient metal-free electrocatalyst for oxygen reduction reaction (ORR) which was prepared through MgO template directed approach by in situ sulfur doping based on the pyrolysis of p-methylbenzenesulfonic acid. The as-obtained electrocatalyst features distinctive porous graphene frameworks and uniform distribution of sulfur dopants with highly active sites. When employed for ORR, such catalyst shows pronounced catalytic activity, improved stability and better resistance toward methanol crossover than those of the commercial Pt/C, and a nearly four-electron transfer number in alkaline media.