An overview on non-platinum cathode catalysts for direct methanol fuel cell

Platinum is the most effective electro-catalyst for oxidation and reduction processes in direct methanol fuel cells (DMFCs). Although platinum and its alloys show desirable electrochemical activities, these catalysts are expensive and make the commercialization of DMFC less attractive. Beside, literature reviews show that tremendous improvements of the activity and stability of non-platinum cathode catalysts have been achieved over the past few years. However, problems including low reaction rates, high over-potentials and low stabilities that remain unsolved particularly for cathode catalyst are discussed in this paper. This paper also describes the various types of non-platinum materials that can potentially substitute for platinum cathode catalysts in DMFC like macrocyclic molecules such as porphyrins and phthalocyanines, transition metal oxides, transition metal sulfides, amorphous transition metal sulfides, and transition metal-based catalysts. Finally, this paper also summarizes the preparation procedure and the performance of various potential cathode catalysts for DMFC operated in acidic and alkaline media as compared with platinum.