Scientists have developed a new non-platinum catalyst which could pave the way for cheaper and more durable hydrogen fuel cells for use in cars and other devices.
Chemists at Brown University in Rhode Island, USA, have developed a cobalt-graphene combination catalyst which works a little slower traditional platinum catalysts, but is longer-lasting and more sustainable-overcoming the key drawbacks to platinum.
Led by Shouheng Sun, the team from the university developed what they say is they best non-platinum catalyst yet using a graphene sheet covered by cobalt and cobalt-oxide nanoparticles.
The new material “has the best reduction performance of any non-platinum catalyst,” said Shaojun Guo, a postdoctoral researcher in Sun’s lab. The results of the team’s finding are published today in the journal Angewandte Chemie International Edition.
Lab tests performed by Sun and his team showed that the new graphene-cobalt material was a bit slower than platinum in getting the oxygen reduction reaction started, but once the reaction was going, the new material actually reduced oxygen at a faster pace than platinum. The new catalyst also proved to be more stable, degrading much more slowly than platinum over time. After about 17 hours of testing, the graphene-cobalt catalyst was performing at around 70 per cent of its initial capacity. The platinum catalyst the team tested performed at less than 60 per cent after the same amount of time.
Cobalt is an abundant metal, readily available at a fraction of what platinum costs. Graphene is a one-atom-thick sheet of carbon atoms arranged in a honeycomb structure. Developed in the last few years, graphene is renowned for its strength, electrical properties, and catalytic potential.
Ultimately, Sun says, finding a suitable non-platinum catalyst is the key to getting fuel cells out of the laboratory phase and into production. Without this, hydrogen fuel cars would remain prohibitively expensive.
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