Readily fabricated NiCo alloy-metal oxide-carbon black hybrid catalysts for the oxygen reduction reactions in the alkaline media

Abstract

Highly efficient, cost-effective and environmental-friendly electrocatalysts play a crucial role in oxygen reduction reaction (ORR) for fuel cells and metal-air batteries. Herein, a series of hybrids comprising of NiCo alloy, metal oxides and carbon black were readily prepared by a one-pot pyrolysis approach and employed as efficient ORR electrocatalysts in the alkaline media. Different amounts of Ketjen Black EC 300J (EC) with a large mesoporous area and exceptional electrical conductivity were directly added to synthesize the hybrids. Among the hybrids tested, the NC-MMO-EC-3 (where NC stands for NiCo alloy and MMO for mixed metal oxides) with an appropriate amount of EC displayed the best ORR electrochemical activity. The enhanced activity of the NC-MMO-EC-3 could be attributed to the conductivity improved by EC, the high dispersion of MMO and NC on EC support, and the beneficial interaction among those three components.