Authors: Siahkalroudi, ZM; Aghabarari, B; Vaezi, M; Rodriguez-Castellon, E; Martinez-Huerta, MV

Article.
Mol. Catal.. vol: 502. page: 2468-8231.
Date: FEB. 2021.
Doi: 10.1016/j.mcat.2020.111372.

Abstract:
Heteroatomic dual-doped metal free graphene materials have revealed significant improvement in the electrocatalysis properties for oxygen reduction reaction (ORR) in alkaline anion exchange membrane fuel cells. Here we report a straightforward and cost-effective strategy to fabricate N, S- and N, P- dual-doped reduced graphene oxide electrocatalysts, characterized by similar N/S and N/P ratios. For this purpose, we used ammonium sulfate ((NH4)2SO4) and ammonium monohydrogenphosphate ((NH4)2HPO4) as heteroatom precursors to obtain the desired catalysts by pyrolysis with graphene oxide. Systematic characterization reveals that the secondary heteroatom S has a greater promotional effect than P in ORR. Furthermore, the gap between the onset potentials of N, S- dual-doped graphene and the standard Pt/C is only 30 mV. The results imply that the combination of the N, S heteroatoms and the surface structure in dual-doped reduced graphene oxide lead to a synergistic effect in catalyzing ORR in alkaline media..