This new material could potentially be used for efficient hydrogen generation without rare and precious metals like platinum. The researchers have published their findings in the scientific journal ACS Nano.
“Currently, the most efficient electrolysers contain platinum and iridium, which are needed for the electrodes on which the hydrogen and oxygen gas are produced from water,” explains Dr. Chris Baeumer, researcher and assistant professor at the University of Twente. “However, platinum and especially iridium are too rare. That’s why we’re constantly looking for electrode materials made from more abundant resources which also can be used as efficient and stable electrocatalysts.”
Dr. Baeumer and his team found exactly what they were looking for in a new material, which is a compound containing five different transition metals.
Individually, the five transition metals are only moderately active when used as a catalyst. However, the researchers found that the combined activity outperforms the individual compounds by a factor of up to 680. The higher activity comes as a surprise, explains Dr. Baeumer: “We expected that the stability compared to traditional composites would be enhanced, but when we started testing it soon turned out that the activity was much higher too. In collaboration with our partners from Karlsruhe (Germany) and Berkeley (USA), we found that the individual transition metals may ‘help’ each other to make the combined material better than the sum of its parts in a so-called synergy effect.”
Combining the five different materials is complex, however, and the activity has so far been tested only in a lab environment. “We’re comparing a newly discovered composite to materials optimised for large-scale production, meaning that our new material still needs to be tested on the industrial scale,” explains Shu Ni, postdoc at the University of Twente, who is leading these future developments for materials optimisation. “However, with some tweaking and further research, this combination of transition metals has the potential to outperform currently available alternatives,” he concludes.