Nickel–Cobalt–Phosphide Catalyst Derived from MOF-74 for Oxygen Reduction Reactions

Abstract

In recent years, energy conversion and storage systems have been playing a crucial role in alleviating the pressure of energy crisis. Oxygen reduction reactions (ORRs) play an important role in energy conversion and storage systems, such as fuel cells and metal air batteries. Herein, it is critical important to develop high efficient and stable electrocatalysts for ORRs to replace platinum-based catalytic materials. In this work, nickel-cobalt bimetallic metal-organic framework (NiCo-MOF-74) and its derivatives (oxide, phosphide and sulfide) were synthesized and their electrochemical performances for ORRs were evaluated. The series of NiCo-MOF-74 products with rod-like structure show excellent electrochemical performance, especially phosphide. The phosphide exhibits higher current density, excellent methanol tolerance and long-term stability compared with the Pt/C catalyst. Therefore, the series of NiCo-MOF-74 derivatives have great potential in ORRs as highly active, stable and low-cost catalysts.