Nickel-Cobalt Metal-Organic Framework CPO-27 and g-C3N4 for Oxygen Reduction Reaction in Alkaline-Exchange-Membrane Fuel Cell

This study synthesizes the nickel-cobalt supportedby themetal-organic framework CPO-27 (coordination polymer of Oslo,Ni-Co-CPO-27) and g-C3N4, showing outstandingcatalytic activity and stability for oxygen reduction reaction inalkaline media, notated by NiCo2-CPO-27/PCN-HT (PCN-HT:heat-treated polymeric carbon nitrite). The half-wave potential ofNiCo(2)-CPO-27/PCN-HT is 0.82 V, and the electron transfernumber is around 3.99, which is close to the activity of Pt/C. Thestability test of NiCo2-CPO-27/PCN-HT demonstrates only0.01 V decade of the half-wave potential after 30,000 cycles. Thesynergistic effects of Ni-Co metals, pyridinic-N species, andgraphitic-N species contribute to the outstanding performance of NiCo2-CPO-27/PCN-HT. The anion exchange membrane fuel cell (AEMFC)using NiCo2-CPO-27/PCN-HT in the cathode shows excellentperformance with a maximum power density of 224.4 mW cm(-2), 20% higher than AEMFC using the Pt/C under the same condition.