Nitrogen-Doped Carbon with Non-Precious Metals as Efficient Catalyst for Oxygen Reduction and Na2CO3 Electrolysis.

Developing oxygen reduction reaction (ORR) catalysts with high activity and low cost is a challenge in the field of electrochemical energy conversion. Here, an efficient catalyst of N-doped carbon with non-precious metals (Mn, Fe, Co, and Ni) designated as MFCN/NC has been prepared by using a simple pyrolysis method. Pyridinic nitrogen, graphitic carbon, MnO, and Fe-Co-Ni nanoparticles, which are efficient for catalyzing the ORR individually or synergistically, are successfully introduced into the composite catalyst. The optimized MFCN/NC catalyst exhibits four-electron reduction of O₂ with a more positive ORR onset potential (54 mV) and a more positive half-wave potential (46 mV) than commercial Pt/C. Moreover, MFCN/NC shows remarkable electrocatalytic activity and long-term stability in Na₂CO₃ electrolysis. The cell voltages at 10 and 100 mA cm⁻² are only 0.86 and 1.45 V, respectively, suggesting an energy-saving electrolysis of Na₂CO₃ to regenerate NaHCO₃ and NaOH. [ABSTRACT FROM AUTHOR]