Catalyst free hydrogen generation from directly disulfonated poly(arylene ether sulfone) copolymer membranes

Abstract

In this study, catalyst free hydrogen generation for proton exchange membrane fuel cells (PEMFC) from directly disulfonated poly(arylene ether sulfone) copolymer membranes (BPSH) has been successfully achieved. A two-compartment reactor where an acid solution was separated from sodium borohydride solution via a proton exchange membrane was used to evaluate hydrogen generation capacity. Hydrogen generation rate was simply controlled by tailoring the proton conductivities of the membranes. For this purposes, BPSH membranes at various percent degrees of disulfonation (25, 35 and 45 molar percent) have been prepared. The hydrogen generation performances of both BPSH and the state of art membrane, Nafion™ have been explored. Hydrogen generation rates were observed as 124, 175, 235 and 151.3mLmin−1 for BPSH 25, 35, 45 and Nafion™, respectively. The influence of temperature on hydrogen generation rates was also investigated. It was demonstrated that the hydrogen generation performance of Nafion™ was deteriorated at temperatures higher than 80°C due to considerable loss in its proton conductivity. Last but not least, we have demonstrated that a fuel cell has been powered along 300h with highly stable catalyst free hydrogen generation.