Working in the Vijay Ramani lab at the McKelvey School of Engineering at Washington University in St. Louis, a team of researchers have found an excellent bifunctional catalyst for the oxygen electrode for regenerative fuel cells.
A single device that both generates fuel and oxidant from water and, when a switch is flipped, converts the fuel and oxygen into electricity and water, has a host of benefits for terrestrial, space and military applications. From low environmental impact to high energy density, developing efficient unitized regenerative fuel cells, or URFCs as they are called, has been in researchers’ sights for years now.
But to truly be efficient, an URFC needs bifunctional catalysts. This means, in electrolyzer mode, catalysts should facilitate the breakdown of water into hydrogen and oxygen, and, in fuel cell mode, facilitate their recombination into water.
The team of researchers found that a composite of platinum and a lead ruthenate pyrochlore made an excellent bifunctional catalyst for the oxygen electrode.
“Unlike the hydrogen electrode, wherein platinum is an effective bifunctional catalyst, it is very challenging to identify a suitable catalyst for the oxygen electrode due to the sluggish kinetics of oxygen reduction and oxygen evolution,” said Pralay Gayen, currently working at Intel, who was a postdoctoral research associate in Vijay Ramani’s lab at the McKelvey School of Engineering at Washington University in St. Louis and served as the paper’s first author.