Design of a non-precious metal electrocatalyst for alkaline electrolyte oxygen reduction by using soybean biomass as the nitrogen source of electrocatalytically active center structures

摘要

The development of less expensive, more active, and more stable catalyst substitute for Pt/C catalysts for oxygen reduction has recently become a hot topic. In this paper, we report a new strategy to design nitrogen-doped non-precious metal catalysts via the copyrolysis of metallic iron, soybean biomass, and carbon support at high temperatures. The results show that the nitrogen in electrocatalysts is mainly in the form of pyridinic and pyrrolic N species. The metallic Fe in the precursor can facilitate the transformation of quaternary N with a three-dimensional structure to planar pyridinic and pyrrolic N inside carbon matrix during pyrolysis, thereby improving the electrocatalytic activity of the prepared catalysts. We suggest that the planar N species may be the catalytically active center structures and may contribute to the enhancement of oxygen reduction reaction performance in an alkaline electrolyte. The prepared catalyst has superior tolerance against methanol crossover effect and outstanding stability compared with commercial Pt/C catalysts.