Facile synthesis of N, P-doped hierarchical porous carbon framework catalysts based on gelatin/phytic acid supermolecules for electrocatalytic oxygen reduction

Abstract

The design of porous carbon frameworks with high-density distributions of dopant sites, especially those derived from renewable biomaterials, is highly desirable to improve the activity of nonprecious porous carbon catalysts for oxygen reduction reaction (ORR). In this paper, we prepared N, P-doped hierarchical porous carbon catalysts via a direct pyrolysis of a gelatin/phytic acid supermolecular aggregate without extra activation processes. The optimal catalyst materials (NPC1000) showed not only the highest N and P contents but also the highest specific surface area, total pore volume and mesoporous pore volume, which are also higher than those of the contrast sample prepared with a chitosan/phytic acid supermolecular aggregate. Thus, the sample NPC1000 had the best electrocatalytic activity compared with the Pt/C catalyst, which was nearly a direct four-electron reaction. The sample also had higher stability and methanol tolerance than Pt/C. This work provides a simple, economical and environmentally friendly method to prepare nonprecious porous carbon catalysts with the desired properties.