Theoretical investigation of the use of doped graphene as a membrane support for effective CO removal in hydrogen fuel cells

Abstract

Carbon monoxide poisoning of the anode catalyst is currently a big problem facing the use of hydrogen fuel cells. This study uses density functional theory to model the interaction between a filter membrane and carbon monoxide to optimise the removal of CO from the H₂ feed gas. The membranes studied are graphene/metal surfaces of nickel, platinum and iridium/gold over undoped or boron-, nitrogen- or oxygen-doped graphene. It was found that graphene doping improved the efficiency of the filter membrane in hydrogen fuel cells because addition of a dopant increases metal/graphene binding and causes metal/H₂ binding to become negligible while only decreasing metal/CO binding slightly. Platinum and iridium/gold systems show slightly stronger binding to graphene and CO than nickel systems. However, nickel is a non-precious metal, so membranes produced with this active centre could lead to a reduction in the cost of fuel cell production by increasing the lifetime of the platinum anode catalyst.

Keywords:

• carbon monoxide removal
• doped graphene support
• density functional theory

Acknowledgements

This study was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Defense and Security Research Institute-Royal Military College Defense Academic Research (DSRI-RMC DAR) Programme and the Royal Military College of Canada.