Tofu-derived nitrogen-doped mesoporous carbon materials as metal-free catalyst for oxygen reduction reaction

摘要

Nitrogen dope mesoporous carbon materials are widely used in the designing of oxygen reduction reaction (ORR) catalysts. How to prepare nitrogen-doped carbons (NC) with broad mass transfer path and preserve abundant ORR active nitrogen functionalities is still a great challenge. Here, nitrogen-doped mesoporous carbon materials are obtained through simply pyrolysis a mixture of renewable biomass (tofu) and ZnCl2. Owing to the effective chemical activation effect during carbonization, the optimal NC could present high porosity (high surface area of 1062m(2)g(-1), large pore volume of 0.97cm(3)g(-1)) and high nitrogen content (7.74wt%). Benefit from the rich of nitrogen functionalities to create abundant active sites and the well-developed mesoporous structure (high mesopore area 825m(2)g(-1) and dual mesopore system with mesopore in both 3nm and 30nm) to guarantee fast mass transport and electron transfer, the obtained NC could serve as fine metal-free ORR catalyst, accelerating oxygen reduction reaction via high efficient 4e(-) oxygen reduction pathway. And more important, NC showed higher stability than commercial Pt/C (20wt%), which highlight its great potential in the designing of electrocatalyst.