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Hydrogen advocates have a habit of ignoring the obvious constraint sitting at the core of their preferred technology. They speak of cost declines, of economies of scale, and of green hydrogen pipelines, but rarely acknowledge that the chemistry of proton exchange membrane fuel cells depends on a scarce and irreplaceable metal. In a recent article, I looked at Alstom’s hydrogen trains, which have been sidelined and pushed back to diesel because Cummins could not deliver replacement fuel cells. Following that thread back revealed that platinum shortages are at the heart of the problem. The truth is that if a handful of trains run into trouble, the story only gets worse when you imagine millions of cars, trucks, and buses depending on the same scarce catalyst.
Platinum is the key to making PEM fuel cells work. It splits hydrogen molecules at the anode, allows protons through the membrane, and accelerates the slow reaction that combines oxygen with electrons and protons at the cathode. No platinum means no practical fuel cell. Global platinum supply is about 250 to 280 tons per year. Roughly a third goes into automotive catalytic converters, another quarter goes into jewelry, about a fifth goes into industrial catalysts, and the rest is split among glass, electronics, and a few emerging uses. The market is already in deficit, with shortfalls of about 30 tons a year and inventories running thin. Prices have been climbing, and lease rates for physical metal have spiked. That is the market context into which hydrogen for mobility is trying to insert itself.
Electrolysis faces a different set of material challenges than fuel cell vehicles because not all electrolyser types depend on platinum. Proton exchange membrane electrolysers do use platinum and iridium at the electrodes, but their share of the market is still relatively small compared to alkaline systems, which rely on abundant materials like nickel and iron. Solid oxide electrolysers avoid platinum entirely by operating at high temperatures with ceramic materials. Even within PEM designs, platinum loadings are lower than in heavy-duty transport stacks, and iridium scarcity rather than platinum is the main bottleneck. This means that while platinum supply can slow the growth of PEM electrolysis, the sector has technological alternatives that allow scaling without being locked into a single irreplaceable metal. Fuel cell vehicles do not have that flexibility.
To understand the scale of the problem, it is worth running scenarios. A typical passenger fuel cell car uses a stack of about 100 kW. At realistic loadings of 0.13 to 0.18 g of platinum per kW, that is 13 to 18 g of platinum per vehicle. 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 only 10 percent of global vehicle sales were fuel cell based, that would require 159 to 226 tons of platinum per year. That is 60 to 90 percent of the entire global platinum market, leaving little or nothing for refining, diesel aftertreatment, or jewelry. A 50 percent hydrogen vehicle world would need around 800 to 1,100 tons per year, while a 100 percent scenario would consume 1,600 to 2,300 tons annually. Even the lowest scenario consumes nearly the whole market.
These numbers become more vivid when converted into geology. South African platinum ores often contain 2 to 6 g of platinum group metals per ton of rock. Industry metrics suggest 10 to 40 tons of ore must be processed to extract a single troy ounce of platinum. On that basis, each ton of platinum requires the movement and processing of 320,000 to over 1.2 million tons of ore. At the low end of the 10 percent hydrogen scenario, with demand of about 160 tons, the industry would need to mine and process over 50 million tons of rock each year on top of today’s production. At the upper end, over 200 million tons of ore would be required. To put that in context, that is more rock than was excavated to build the Panama Canal. It is about half the annual volume of iron ore mined in Australia. Scaling hydrogen transport means trying to add a new mining industry the size of the copper sector, but dedicated entirely to one scarce metal.
Hydrogen advocates respond to this in a few predictable ways. They point out that platinum loadings have fallen by 80 percent from the earliest stacks, which is true. They point to closed loop recycling programs that can recover 95 percent of platinum from end of life stacks, which is true in controlled pilot conditions. They highlight research into PGM free catalysts and alkaline membranes, which is real but not commercial. The problem is that none of these measures changes the fundamental constraint. Heavy duty stacks still need 0.4 to 0.6 g per kW for durability, and shaving that number further is difficult. Recycling only helps after a fleet has been built and retired, it does not provide the initial volumes needed to scale. PGM free catalysts remain in the lab, and their performance and lifetimes have yet to meet the requirements of heavy transport.
If hydrogen vehicles grabbed 10 percent of the market, platinum demand would jump by half. Market analysis shows that platinum supply and demand are price inelastic in the short term. A 50 percent increase in demand in a deficit market with fixed supply is likely to double or triple the price. That would push platinum from $1,300 per ounce to $2,600 or even $3,900. At those prices, the platinum in a single passenger car stack would add $1,600 to $2,200 in cost. In a heavy truck it would add $15,000 to $22,500. In a bus the increase would be $5,000 to $11,000. Those costs come on top of the other disadvantages of fuel cell vehicles compared to batteries, including poor efficiency and higher infrastructure costs.
Batteries are not without their own metal requirements, but there is no equivalent choke point. Nickel and cobalt can be avoided by shifting to LFP chemistries. Lithium can be avoided in some applications by sodium ion. Manganese and iron are abundant. The constraints in batteries are around factory build out and supply chain organization, not a single scarce and irreplaceable element. In platinum the hydrogen sector has no such escape hatch. Without platinum, PEM fuel cells do not function, and there is no realistic substitute at scale.
This leads back to the question of honesty in the hydrogen narrative. Platinum shortages have been known for years. Industry roadmaps acknowledge the problem but present targets and aspirations as if they were near term realities. The reality is that even modest adoption would consume the bulk of the global platinum market, require moving mountains of rock, and drive platinum prices high enough to make hydrogen vehicles unaffordable. The Alstom trains already showed what happens when the constraint bites. At global scale the problem is not a technical hiccup but a fundamental limit. Energy transitions succeed when technologies can scale with abundant resources. Batteries meet that test. Hydrogen for road transport does not.
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