‘An ominous task’ — filling the demand for clean hydrogen & required PGMs: Green Rush’s Matt Watson

Green Rush host Matt Watson says "an awesome amount" of material will be needed for clean hydrogen applications, but guest Phillip Walter believes technology will provide solutions. 

On April 17, Watson recorded an episode of Green Rush with Walter, Executive VP of Business Line Hydrogen Systems for Heraeus, a major precious metals processor. The topic was the hydrogen economy and platinum group metals (PGMs). 

Walter said PGMs and hydrogen belong together because they have a unique position in geochemistry. Applications include electrocatalysts to produce hydrogen, Proton Exchange Membrane (PEM) electrolysis, electrocatalysts for electrolysis, the coating of bipolar plates or porous transfer layers to protect against corrosion, and removing oxygen from a hydrogen stream. 

One of the biggest future applications of hydrogen is in fuel cells, where platinum on carbon-type catalysts are used for synthesizing water out of hydrogen and oxygen, thus releasing energy. 

Watson clarified the difference between PEM electrolyzers, used for producing "green" hydrogen, and PEM fuel cells, which take hydrogen gas and convert it to power, mostly to drive transportation systems. 

Iridium and platinum are used in PEM electrolysis, while platinum is essential for fuel cells, along with iridium as a cell reversal additive. 

The rarity of iridium has necessitated thrifting; Walter said a lot less iridium per gigawatt is used now, about 400 kilograms per GW versus a tonne per GW two years ago. The total electrolyzer capacity is around 70 GW. It is estimated that about 28 tonnes will be needed by 2030 versus about 12 tonnes available for new applications, leaving a shortfall. 

Eight to 10 tonnes of iridium are produced annually as a by-product of platinum mining. 
"This is a minor subset of the platinum group metals, very small and yet so crucial," Watson said. "That's why you hear so much discussion about iridium. How are we going to design-thrift this to get it to be scalable?"

The Hydrogen Council is eyeing 600-900 million tonnes of clean hydrogen by 2050, including for fuel cell vehicles, "green" steel, green methane, and green ammonia, used as a fuel feedstock in maritime shipping. "This is an ominous task. How much clean hydrogen are we gonna need? It's an awesome amount of material," Watson said.