Based on perfluorosulfonic acid polymer membranes (PFSA,e.g.Nafion),polymer electrolyte membrane fuel cells (PEMFC) operate with hydrogen or purified reformate gas due to the strong poisoning effect of fuel impurities.Consequently,a complicated fuel storage or fuel processing system is needed.Direct methanol fuel cells,on the other hand,suffer from slow anodic kinetics and therefore low power density.The newest technology in the field is the development of temperature resistant polymer membranes for operation at temperatures higher than 100°C.The high temperature PEMFC exhibits performance compatible with PFSA based PEM fuel cell but can tolerate up to 3 %(volume fraction) carbon monoxide.The high CO tolerance makes it possible to use the reformed hydrogen directly from a simple methanol reformer without further CO removal.This opens possibility for an integrated reformer fuel cell system,which is expected to exhibit high power density and simple construction as well as efficient capital and operational cost.
