Direct methanol fuel cells system-A review of dual-role electrocatalysts for oxygen reduction and methanol oxidation

摘要

One fundamental challenge in exploiting direct methanol fuel cells(DMFCs)is the preparation of inex-pensive,high active electrocatalysts,which are highly active and durable for the two half-reactions,i.e.,the methanol oxidation reaction(MOR)at the anode and the oxygen reduction reaction(ORR)at the cathode.Platinum group metals-based catalysts have been known the governing dual-functional electro-catalysts based on the literature reports.But these catalysts are expensive and commercialize the DMFC less attractive.In addition to the high-cost,there are also methanol crossover,CO poisoning,long-term instability,and other problems as for Pt-based spurs.For the dual-role MOR&ORR catalysts,methanol crossover is inevitable to a certain extent on the current development of DMFC with losses in terms of cell voltage.In this regard,one strategy is to exploit high selective anodic/cathodic electrocatalysts to cap-italize the energy density at a high concentration of methanol.According to the summary results,there are mainly two types of dual-role electrocatalysts:one is Pt-support/co-catalyst(designated as P-S/C)for MOR/ORR,the other is catalyst/co-catalyst(designated as C/C)for MOR/ORR.This paper aims to review the design and construction of the various dual-role catalysts and give some discussion briefly.