N- and S-doped nanoporous carbon framework derived from conjugated microporous polymers incorporation with ionic liquids for efficient oxygen reduction reaction

Abstract

The rapid growth of high-performance metal-free electrocatalysts is of great significance for widespread realization of fuel cells since noble metals (e.g. platinum) used as electrocatalysts have long been considered as major bottleneck which limited their commercialization. Herein, we report the creation of a kind of novel porous carbon framework containing dual heteroatoms (N and S, named as C-CMPs-NS), which was fabricated by direct pyrolysis of ionic liquids loaded on conjugated microporous polymers, application of highly efficient metal free electrocatalyst in oxygen reduction reaction (ORR). Due to their large specific surface area, outstanding porosity and, significantly, active sites exposed own to high density doping of S and N, the catalyst showed good oxygen reduction reaction activity in alkaline electrolyte. The C-CMPs-1NP yielded a half-wave potential of 0.82 V, high onset potential (0.98 V vs. RHE), the high diffusion limiting current density of 4.2 mA cm−2 and better methanol tolerance than commercial Pt/C where nearly no ORR polarization curve shift and no change of oxygen reduction peak in cyclic voltammetry (CV) were observed in 3.0 M methanol solution. Based on these merits mentioned above, the C-CMPs-NS may hold great potentials as promising alternative of precious metal catalysts for next generation fuel cells.