Recent progress in the development of anode and cathode catalysts for direct methanol fuel cells

Abstract

Continuous growth in global energy demand has sparked concerns about energy security and environmental sustainability. In the past two decades, attempts have been made in the development of innovative energy technologies. The direct methanol fuel cell (DMFC) is among the most promising alternative energy sources for the near future. Simple construction, compact design, high energy density and relatively high energy-conversion efficiency give the DMFC an advantage over other promising power sources in terms of portability. However, the translation of DMFCs into commercially successful products is precluded due to poor performance. In addition, low activity, poor durability and reliability and an expensive anode and cathode further discourage the application of DMFCs. In this regard, the present review article focuses on recent progress in the development of anode and cathode catalysts for DMFCs. The first part of the review discusses the recent developments in the synthesis of single-, double-, and multiple-component catalysts and new catalyst supports for anode electrodes. The section is followed by the chemical approaches employed to make alloys and composite catalysts, aiming to enhance their activity, reliability and durability for the methanol oxidation reaction. Finally, exciting new research that pushes the development of single-, double-, and multiple-component catalysts and new catalyst supports for cathode electrodes is introduced. In addition, size-, shape- and composition-dependent electrocatalysts that are advocated for methanol oxidation at the anode and oxygen reduction at the cathode are highlighted to illustrate the potential of the newly developed electrocatalysts for DMFC applications. Moreover, this article provides a comprehensive review of the experimental work that is devoted to understanding the fundamental problems and recent progress in the development of anode and cathode catalysts for DMFCs.