Electrocatalytically active graphene-porphyrin MOF composite for oxygen reduction reaction.

Pyridine-functionalized graphene (reduced graphene oxide) can be used as a building block in the assembly of metal organic framework (MOF). By reacting the pyridine-functionalized graphene with iron-porphyrin, a graphene-metalloporphyrin MOF with enhanced catalytic activity for oxygen reduction reactions (ORR) is synthesized. The structure and electrochemical property of the hybrid MOF are investigated as a function of the weight percentage of the functionalized graphene added to the iron-porphyrin framework. The results show that the addition of pyridine-functionalized graphene changes the crystallization process of iron-porphyrin in the MOF, increases its porosity, and enhances the electrochemical charge transfer rate of iron-porphyrin. The graphene-metalloporphyrin hybrid shows facile 4-electron ORR and can be used as a promising Pt-free cathode in alkaline Direct Methanol Fuel Cell.