Combustion reaction-derived nitrogen-doped porous carbon as an effective metal-Free catalyst for the oxygen reduction reaction

Finding an effective approach to prepare low-cost metal-free catalysts with excellent catalytic performance for the oxygen reduction reaction (ORR) is a crucial challenge for the commercialization of fuel cells. Herein, a novel and effective combustion approach was designed in order to construct the three-dimensional porous carbon foam and followed by heat treatment in an NH3 atmosphere. In the combustion process, sucrose was used as the carbon source to produce the carbon framework, sodium bicarbonate as the pore-foaming agent to form the porous structure. This synthetic route is novel, cost-effective and without using any templates, expensive equipment as well as highly toxic chemical reagents. Compared with the control samples, the typical product exhibits the excellent catalytic activity in terms of not only a positive onset potential and high current density, but also low H2O2 yield and approximate four-electron reaction pathway in alkaline media. The reason may be attributed to the synergistic effect of the three-dimensional porous structure, high BET surface area (up to 1216 m2 g−1) and effective nitrogen-doping of the product. In addition, the novel method is of great importance, which may guide future efforts for the development of other porous carbon-based materials for applications in multi-fields.