Platinum group metal (PGM) catalysis can play as an essential decarbonising role beyond hydrogen generation, where its use in proton exchange membrane (PEM) technology for water electrolysis and fuel cells is being increasingly seen as essential.

As has been reiterated for some time, PGMs and hydrogen belong together. But now being posited that the decarbonising effect of these largely Southern African-sourced special metals could well extend significantly beyond planet-protecting green hydrogen into carbon dioxide biomass as well perhaps even polymer waste.

To treat these, PGM catalysis can, once again, play as an essential role.

This is the main takeaway from Mining Weekly's interview with Dr Philipp Walter, the executive VP Business Line Hydrogen Systems, Global Business Unit Heraeus Precious Metals, now returned from his recent presentation at the New York Platinum Week. (Also watch attached Creamer Media video.)

On the one hand, PGMs main applications are as electro catalysts for electrolysers, and on the other hand for fuel cells, which turn the hydrogen back into green electricity.

Mining Weekly: Why is green hydrogen such a key solution when it comes to clean fuel, energy storage, decarbonisation, and the greening crucial materials?

Walter: Hydrogen is an energy vector in this respect, so it has an ability, when being formed by means of electrolysis, to store energy and this stored energy can then either be released through fuel cells, through chemicals or through use as fuels, so it can be burned, and then you have only water as a byproduct and not any other carbon containing compounds.

New York heard that PGMs are building a toolbox for hydrogen applications. Tell us about that.

PGMs are toolbox because of their synergistic effects. They have a different cost profile, and basically, depending on a certain target application, what you can do is mix PGMs to achieve a certain target property profile, including a certain cost profile, which has been done in many instances in the past for emission catalysts.

What is the relationship between water electrolysis and PGMs?

There are different water electrolysis technologies, and a lot of these technologies apply PGMs. The major use, however, is foreseen for PEM electrolysis, where platinum is used on the cathode for what is called the hydrogen evolution reaction, and iridium, or iridium and ruthenium, are used on the anode for the oxygen evolution reaction.

What is the latest when it comes to hydrogen electrolyser development how competitive is hydrogen electrolysis?

Water electrolysis, and PEM electrolysis, which is where the PGMs are predominantly used, is developing, and one of the clear targets is to reduce the cost. PGMs bear a certain cost in an electrolyser, but by means of thrifting as well as advanced development, these costs can be reduced by the load of PGMs being reduced, without sacrificing the performance of the respective electrocatalysts for the hydrogen evolution and the oxygen evolution reaction.

Is the world accepting this?

The world is increasingly accepting the fact that PGMs are essential parts of the PEM technology for water electrolysis as well as fuel cells. There are often attempts to reduce, or even to replace PGMs, but, so far, the peculiar electrochemical stability of PGMs, together with their activity, makes them very hard to replace, so industry is, I think, accepting the fact that PGMs are an essential part of PEM technology.

LATEST PGM-LINKED HYDROGEN ADVANCES

The World Platinum Investment Council reports that Siemens Energy has been contracted to supply and install the electrolysers needed for the 100-MW Hamburg Green Hydrogen Hub to be built at the site of a decommissioned coal-fired power station in the Moorburg district. The order is for six units of Siemens Energy's latest PEM electrolyser model. The stacks will be fabricated at the company's new Gigafactory in Berlin and assembled at its Muhlheim site and at a European partner.

Fuel C...