Efficient Pt-free electrocatalyst for oxygen reduction reaction: Highly ordered mesoporous N and S co-doped carbon with saccharin as single-source molecular precursor

Abstract

Despite that nitrogen (N) and sulfur (S) co-doped ordered mesoporous carbon (OMC) as Pt-free catalyst for oxygen reduction reaction (ORR) shows a desirable performance, the synthesis method is always complicated and expensive, which greatly hinders its development and application. In the present work, a highly ordered mesoporous N and S co-doped carbon material is developed. The material is obtained by combining hard template and high-temperature pyrolysis method using cheap saccharin as a single-source molecular precursor, SBA-15 as the hard template and FeCl3 as the catalyst to promote the carbonization process. It is found that the as-prepared SN-OMC catalyst, compared with the commonly used commercial Pt/C (20 wt.%), exhibits comparable ORR electrocatalytic activity with mainly four-electron (4e-) process, superior stability and inertness to methanol in alkaline media, which could mainly benefit from the highly ordered mesoporous structure and the synergistic effect caused by the dual N and S doping. These advantages render SN-OMC a promising ORR electrocatalyst and a cheap alternative to Pt/C for practical fuel cell applications. © 2016.