Triptycene copolymers as proton exchange membrane for fuel cell - A topical review

In view of the pressing need for alternative clean energy source to displace the current dependence on fossil fuel, proton exchange membrane fuel cell (PEMFC) technology have received renewed research and development interest in the past decade. The electrolyte, which is the proton exchange membrane, is a critical component of the PEMFC and is specifically targeted for research efforts because of its high commercial cost that effectively hindered the widespread usage and competitiveness of the PEMFC technology. Much effort has been focused over the last five years towards the development of novel, durable, highly effective, commercially viable, and low-cost co-polymers as alternative for the expensive Nafion® proton exchange membrane, which is the current industry standard. Our primary review efforts will be directed upon the reported researches of alternative proton exchange membrane co-polymers which involved Triptycene derivatives. Triptycene derivatives, which contain three benzene rings in a three-dimensional non-compliant paddlewheel configuration, are attractive building blocks for the synthesis of proton exchange membranes because it increases the free volume in the polymer. The co-polymers considered in this review are based on hydrocarbon molecular structure, with Triptycene involved as a performance enhancer. Detailed herein are the development and current state of these co-polymers and their performance as alternative fuel cell electrolyte.