Low-Cost Catalyst Could Replace Platinum in Fuel Cells

Chemists at Brown University are developing a cobalt catalyst for fuel cells that lasts longer and closely matches the performance of more expensive platinum-based alternatives.

The new material consists of graphene a one-atom-thick array of carbon atoms that has been coated with a single layer of cobalt and cobalt oxide nanoparticles.

Fuel cells require a catalyst on the cathode side. The researchers say oxygen acts as an electron sink, stripping electrons from hydrogen at the anode and creating the electrical pull that causes current to flow. Platinum has been the most efficient catalyst for that task.

The material developed at Brown takes longer to begin the desired oxygen reduction process but then becomes more efficient and significantly longer-lasting than platinum in maintaining the reaction, according to the researchers.

The team makes its catalytic material by dispersing cobalt and graphene nanoparticles in separate solutions and using sound waves to mix them. The process causes the cobalt particles to attach evenly to graphene. A centrifuge then removes the material from solution.

The researchers allowed the cobalt particles to oxidize by exposing the material to air. They could vary the thickness of oxidation by controlling how long the material was heated. The team says a layer one nanometer thick produces the best catalytic properties.

The Brown team reports its results HEREin the online journal Angewandte Chemie International Edition.