The supply of critical metals could constrain China's low-carbon transition in hydrogen production

The supply of critical metals could constrain hydrogen production's low-carbon transition, yet China's vulnerability remains underexplored. This study evaluates supply risks and recycling potential for ten critical metals related to hydrogen produced via water electrolysis. Findings show that platinum and iridium (for electrolysis) and antimony (for photovoltaics) face high supply risks. Over the next 40 years, the cumulative demand for these metals could reach 25 %–90 %, 60 %–200 %, and 13–49 times their current annual consumption, respectively. The supply risks could be alleviated after 2040 through the recycling of retired metals, with secondary metals potentially meeting nearly 50 % of the annual demand for titanium, platinum, and iridium. A more radical transition could reinforce the “inverted-U” trend in metal demand and boost secondary metal use by increasing retired metal supply and reducing demand for newly installed capacity. China should strengthen policy guidance and international collaboration to alleviate the supply risks.