Platinum is the key catalyst that makes proton exchange membrane fuel cells work efficiently by speeding the hydrogen and oxygen reactions that produce electricity while remaining stable in the fuel cell environment[2][5].
Why platinum is used and what it does
– Platinum lowers the energy barrier for the hydrogen oxidation reaction at the anode and the oxygen reduction reaction at the cathode, so reactions occur fast enough to give useful power instead of creeping along too slowly[2][5].
– Its chemical stability and resistance to corrosion let it survive the acidic and wet conditions inside polymer electrolyte membrane (PEM) fuel cells where many cheaper materials would degrade[5].
– Because the catalytic activity comes from the metal surface, the practical requirement is surface area rather than bulk metal; that is why researchers disperse platinum as tiny nanoparticles on supports to expose as much active surface as possible while using less metal[1][5].
Challenges with platinum
– Scarcity and cost: platinum is rare, geographically concentrated, and expensive, making it a major fraction of fuel cell cost and a supply-chain vulnerability for scaling hydrogen technologies[1][3].
– Durability and contamination: platinum catalysts can be poisoned by impurities such as carbon monoxide and can degrade over long-term cycling, so maintaining performance is both a materials and engineering challenge[1][2].
– Demand pressure: as electrolysers and fuel cells expand, projected platinum demand grows significantly, creating competition with other industrial uses and stressing supply[6][3].
How industry and researchers reduce platinum use
– Core-shell and atomic-layer methods: techniques like CO-AID deposit ultra-thin platinum shells over cheaper core metals (for example palladium or gold cores with a one-atom-thick platinum shell) to keep high activity while using far less platinum[1].
– Alloying and high-entropy alloys: mixing platinum with other metals or exploring complex alloys aims to reproduce or exceed platinum-like activity with less or no platinum content[5].
– Platinum-free and low-platinum catalysts: research seeks non-platinum catalysts (for example transition-metal-nitrogen-carbon materials) and hybrid catalyst layers that combine tiny amounts of platinum with other materials to maintain durability and performance[2].
– System-level reductions: improving catalyst support structures, membrane and electrode design, and cell architecture can raise the effective activity per gram of platinum, lowering required metal for a given power output[1][5].
Tradeoffs and current state of play
– Substitutes often face durability or activity shortfalls in acidic PEM environments; some promising non-platinum catalysts work better in alkaline systems but are less mature for automotive or long-life applications[2][5].
– Hybrid approaches — using drastically reduced platinum together with other catalysts — are a pragmatic near-term path because they can cut platinum content by large percentages while keeping proven durability characteristics[2].
– New manufacturing and atomic-precision deposition methods can cut platinum loading without sacrificing performance, offering one of the fastest routes to cost reduction at scale[1][6].
Practical implications for users and industry
– For vehicle and heavy-duty applications where energy density and fast refueling matter, platinum-based PEM fuel cells remain the leading technology because of proven performance and durability[5][6].
– For stationary or less demanding uses, alternative chemistries and lower-platinum designs are increasingly viable and may accelerate adoption in niche markets[2][6].
– Broad deployment of hydrogen infrastructure will raise platinum demand, so recycling, better catalyst utilization, and reduced loadings are essential parts of industry plans to keep costs manageable[3][6].
Sources
https://www.intelligentliving.co/carbon-monoxide-co-aid-fuel-cell-catalyst/
https://www.youtube.com/watch?v=jf5dGuuoN7o
https://www.cruxinvestor.com/posts/chinas-strategic-critical-mineral-classification-of-platinum-its-investment-implications-for-global-pgm-supply-pricing-and-emerging-developers
https://goldsell.co.uk/what-is-platinum-used-for/
https://energyinstitute.jhu.edu/the-platinum-problem/
https://www.h2-view.com/story/hydrogen-to-drive-meaningful-platinum-use-but-bottlenecks-lie-with-other-pgms-and-clean-power/2134951.article/