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Hydrogen advocates have a behavior of ignoring the plain constraint sitting on the core of their most popular know-how. They communicate of price declines, of economies of scale, and of inexperienced hydrogen pipelines, however not often acknowledge that the chemistry of proton trade membrane gas cells relies on a scarce and irreplaceable steel. In a current article, I checked out Alstom’s hydrogen trains, which have been sidelined and pushed again to diesel as a result of Cummins couldn’t ship alternative gas cells. Following that thread again revealed that platinum shortages are on the coronary heart of the issue. The reality is that if a handful of trains run into bother, the story solely will get worse if you think about thousands and thousands of vehicles, vans, and buses relying on the identical scarce catalyst.
Platinum is the important thing to creating PEM gas cells work. It splits hydrogen molecules on the anode, permits protons by the membrane, and accelerates the gradual response that mixes oxygen with electrons and protons on the cathode. No platinum means no sensible gas cell. World platinum provide is about 250 to 280 tons per 12 months. Roughly a 3rd goes into automotive catalytic converters, one other quarter goes into jewellery, a few fifth goes into industrial catalysts, and the remainder is cut up amongst glass, electronics, and some rising makes use of. The market is already in deficit, with shortfalls of about 30 tons a 12 months and inventories working skinny. Costs have been climbing, and lease charges for bodily steel have spiked. That’s the market context into which hydrogen for mobility is attempting to insert itself.
Electrolysis faces a distinct set of fabric challenges than gas cell automobiles as a result of not all electrolyser sorts rely on platinum. Proton trade membrane electrolysers do use platinum and iridium on the electrodes, however their share of the market continues to be comparatively small in comparison with alkaline methods, which depend on ample supplies like nickel and iron. Stable oxide electrolysers keep away from platinum totally by working at excessive temperatures with ceramic supplies. Even inside PEM designs, platinum loadings are decrease than in heavy-duty transport stacks, and iridium shortage slightly than platinum is the primary bottleneck. Which means that whereas platinum provide can gradual the expansion of PEM electrolysis, the sector has technological alternate options that enable scaling with out being locked right into a single irreplaceable steel. Gasoline cell automobiles shouldn’t have that flexibility.
To know the size of the issue, it’s price working eventualities. A typical passenger gas cell automobile makes use of a stack of about 100 kW. At real looking loadings of 0.13 to 0.18 g of platinum per kW, that’s 13 to 18 g of platinum per automobile. A heavy truck stack of 300 kW at 0.4 to 0.6 g per kW consumes 120 to 180 g of platinum. A bus stack of 100 to 150 kW consumes 40 to 90 g. If solely 10 p.c of world automobile gross sales have been gas cell primarily based, that might require 159 to 226 tons of platinum per 12 months. That’s 60 to 90 p.c of the complete international platinum market, leaving little or nothing for refining, diesel aftertreatment, or jewellery. A 50 p.c hydrogen automobile world would wish round 800 to 1,100 tons per 12 months, whereas a one hundred pc situation would devour 1,600 to 2,300 tons yearly. Even the bottom situation consumes practically the entire market.
These numbers grow to be extra vivid when transformed into geology. South African platinum ores usually include 2 to six g of platinum group metals per ton of rock. Trade metrics counsel 10 to 40 tons of ore should be processed to extract a single troy ounce of platinum. On that foundation, every ton of platinum requires the motion and processing of 320,000 to over 1.2 million tons of ore. On the low finish of the ten p.c hydrogen situation, with demand of about 160 tons, the business would wish to mine and course of over 50 million tons of rock annually on high of in the present day’s manufacturing. On the higher finish, over 200 million tons of ore could be required. To place that in context, that’s extra rock than was excavated to construct the Panama Canal. It’s about half the annual quantity of iron ore mined in Australia. Scaling hydrogen transport means attempting so as to add a brand new mining business the dimensions of the copper sector, however devoted totally to at least one scarce steel.
Hydrogen advocates reply to this in a number of predictable methods. They level out that platinum loadings have fallen by 80 p.c from the earliest stacks, which is true. They level to closed loop recycling applications that may get well 95 p.c of platinum from finish of life stacks, which is true in managed pilot situations. They spotlight analysis into PGM free catalysts and alkaline membranes, which is actual however not business. The issue is that none of those measures adjustments the elemental constraint. Heavy responsibility stacks nonetheless want 0.4 to 0.6 g per kW for sturdiness, and shaving that quantity additional is tough. Recycling solely helps after a fleet has been constructed and retired, it doesn’t present the preliminary volumes wanted to scale. PGM free catalysts stay within the lab, and their efficiency and lifetimes have but to fulfill the necessities of heavy transport.
If hydrogen automobiles grabbed 10 p.c of the market, platinum demand would bounce by half. Market evaluation reveals that platinum provide and demand are value inelastic within the quick time period. A 50 p.c enhance in demand in a deficit market with mounted provide is prone to double or triple the value. That may push platinum from $1,300 per ounce to $2,600 and even $3,900. At these costs, the platinum in a single passenger automobile stack would add $1,600 to $2,200 in price. In a heavy truck it could add $15,000 to $22,500. In a bus the rise could be $5,000 to $11,000. These prices come on high of the opposite disadvantages of gas cell automobiles in comparison with batteries, together with poor effectivity and better infrastructure prices.
Batteries aren’t with out their very own steel necessities, however there is no such thing as a equal choke level. Nickel and cobalt might be averted by shifting to LFP chemistries. Lithium might be averted in some functions by sodium ion. Manganese and iron are ample. The constraints in batteries are round manufacturing unit construct out and provide chain group, not a single scarce and irreplaceable ingredient. In platinum the hydrogen sector has no such escape hatch. With out platinum, PEM gas cells don’t perform, and there’s no real looking substitute at scale.
This leads again to the query of honesty within the hydrogen narrative. Platinum shortages have been recognized for years. Trade roadmaps acknowledge the issue however current targets and aspirations as in the event that they have been close to time period realities. The fact is that even modest adoption would devour the majority of the worldwide platinum market, require shifting mountains of rock, and drive platinum costs excessive sufficient to make hydrogen automobiles unaffordable. The Alstom trains already confirmed what occurs when the constraint bites. At international scale the issue shouldn’t be a technical hiccup however a basic restrict. Power transitions succeed when applied sciences can scale with ample sources. Batteries meet that take a look at. Hydrogen for highway transport doesn’t.
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