Diversified miner Sibanye-Stillwater and precious metals refiner Heraeus Precious Metals have agreed to collaborate on the research and development of novel electrolyser catalysts containing platinum group metals (PGMs).

These electrocatalysts will be high activity and possess the necessary stability for proton exchange membrane (PEM) electrolysers, which are used in the production of green hydrogen.

Sibanye, which mines platinum, iridium and ruthenium among its basket of PGM products, is looking for ways to invest in market development and technologies that enhance demand for its products.

“Our objective is to ensure our metals, including PGMs, play a vital role in unlocking the future green economy, including hydrogen. The partnership with Heraeus and the investment in the successful development and commercialisation of catalysts for PEM electrolysers will enable another aspect of a greener future,” Sibanye CEO Neal Froneman said in an August 18 statement.

Heraeus has technical and intellectual expertise in the design of electrocatalysts for PEM electrolysis, as well as in terms of developing more sustainable and cost-effective uses of precious metals catalysts.

“With our mutual know-how and resources, we are confident [of developing] novel solutions that will further strengthen the role of PEM electrolysis in the hydrogen economy,” Heraeus new business development executive VP Dr Philipp Walter added.

The novel catalyst project will be equally funded by the two companies over three years, the results of which will be mutually commercialised, with cooperation on all aspects of communication and marketing of the novel catalyst.

Platinum and iridium are currently essential components of electrocatalysts for the generation of green hydrogen by means of PEM electrolysis. However, iridium is one of the scarcest PGMs and its limited availability is a potential constraint on the future widespread adoption of PEM electrolysers.

“Without cost-effective PEM electrolysis, the targets for the ramp-up of the hydrogen economy cannot be achieved. We are ready to invest into a sustainable raw material strategy to make it happen,” Walters said.

Sibanye and Heraeus believe that reducing iridium loadings in PEM electrocatalysts is key to ensuring a sustainable hydrogen ecosystem, enabling PEM technology to be cost competitive enough to make triple-digit gigawatt-scale a reality within the next decade.

Technologies that reduce iridium use or replace it with ruthenium, for example, offer significant potential. The partners, therefore, aim to develop a new and robust solution based on finding ways to substitute iridium with alternative metals, as well as developing more sophisticated metal oxide structures.