Researchers Tout Graphene Proton Filters for Fuel Cells

Graphene, the one-atom-thick carbon lattice first discovered at the U.K.'s University of Manchester, is impermeable to all gases and liquids. But Manchester researchers say protons can easily pass through.

The same is true of a monolayer of hexagonal boron nitride (hBN), according to the scientists. Their discovery suggests the two materials could be used as ultra-efficient proton flow filters an essential component of hydrogen fuel cells or even to extract hydrogen directly from the atmosphere.

Details of the work, which was led by Nobel laureate Andre Geim and includes groups from China and the Netherlands, appears in Nature.

The researchers say boron nitride shows superior proton conductivity at room temperature, but significantly graphene outperforms hBN at higher temperatures (above 250 C). Performance of both materials can be enhanced by covering them with nanoparticles of a catalytic metal such as platinum, according to the team.

The team also show their membranes can be used to extract hydrogen directly from humid air. One researcher says the technique involves simply putting a hydrogen-containing gas on one side, applying a small electric current and collecting pure hydrogen on the other side.

The scientists note they have so far demonstrated only a tiny flow with small membranes. They say the aim of their paper is to alert other developers to the possible new use of graphene and boron nitride.