Graphene-Based Proton Transmission and Hydrogen Crossover Mitigation in Electrochemical Hydrogen Pump Cells

Abstract

A monolayer of single-layer CVD graphene embedded between two Nafion® polyelectrolyte membranes (PEMs) allows for high proton transmission rates through the membrane while also restricting the rate of hydrogen gas crossover through the membrane. Proton transmission occurs through single-layer graphene embedded in Nafion® | graphene | Nafion® PEM sandwich structures with an area-specific resistance (ASR) less than 40 mΩ cm2 for the graphene layer alone at ambient temperature (near 20 C). This ASR value for graphene is less than the ASR of most PEM membranes alone. Hydrogen crossover rates in Nafion® | graphene | Nafion® PEM sandwich structures were measured by a limiting current method and found to be attenuated by more than eight times relative to values in similar membranes without graphene.