The MXene class of materials has many talents. An international team led by HZB chemist Michelle Browne has now demonstrated that MXenes, properly functionalized, are excellent catalysts for the oxygen evolution reaction in electrolytic water splitting.
They are more stable and efficient than the best metal oxide catalysts currently available. The team is now extensively characterizing these MXene catalysts for water splitting at the Berlin X-ray source BESSY II and Soleil Synchrotron in France.
Green hydrogen is seen as one of the energy storage solutions of the future. The gas can be produced in a climate-neutral way using electricity from the sun or wind by electrolytic water splitting. While hydrogen molecules are produced at one electrode, oxygen molecules are formed at the other.
This oxygen evolution reaction (OER) is one of the limiting factors in electrolysis. Special catalysts are needed to facilitate this reaction.
Among the best candidates for OER catalysts are—for example—nickel oxides, which are inexpensive and widely available. However, they corrode quickly in the alkaline water of an electrolyzer and their conductivity also leaves much to be desired. This is currently preventing the development of low-cost, high-performance electrolyzers.
MXenes, layered materials made of metals, such as titanium or vanadium, combined with carbon and/or nitrogen. These MXenes have a huge internal surface area that can be put to fantastic use, whether for storing charges or as catalysts.