Study of the electrocatalytic activity of silicon and nitrogen co-doped carbon towards oxygen reduction reaction

The development of highly efficient and cost effective non-precious metal (NPM) catalysts for fuel cells and metal-air batteries is challenging but of great significance. Although the research and development of non-noble metal and non-metal carbon catalysts for the oxygen reduction reaction (ORR) has gained a lot of attention recently, the electrocatalytic activity of tetravalent metalloids is a less investigated topic. Herein, an effective ORR catalyst based on silica and nitrogen co-doped multi-walled carbon nanotubes (Si,N-MWCNTs) was synthesized via a simple one-pot pyrolysis. The Si,N-MWCNTs catalyst demonstrated exceptional electrocatalytic activity towards the ORR in 0.1 M KOH, with a half-wave potential (E1/2) of 860 mV (vs. RHE). Furthermore, Si, N-MWCNTs displayed apparent stability and excellent tolerance to methanol compared to the commercially available platinum catalyst. Physical characterization was carried out by employing X-ray photoelectron spectroscopy and transmission electron microscopy, which confirmed the integration of both silicon and nitrogen into the carbon structure. These results clearly shed light on the significance of further study on tetravalent metalloids as cost effective and easily available dopants for the preparation of electrocatalysts.