Platinum plays a key role in hydrogen fuel cells by acting as a catalyst that speeds up the chemical reactions needed to produce electricity from hydrogen and oxygen. Without it, these reactions happen too slowly to power things like cars or trucks effectively.
Hydrogen fuel cells work by combining hydrogen gas from a tank with oxygen from the air. This creates electricity, water, and a bit of heat. Inside the cell, there is a special membrane that lets protons pass through while keeping the gases apart. Platinum coats tiny particles or surfaces on both sides of this membrane. At the anode, platinum helps split hydrogen into protons and electrons. The electrons flow through an external circuit to make electricity, while the protons go through the membrane to the cathode. There, platinum helps the protons, electrons, and oxygen combine to form water.https://www.tycorun.com/blogs/news/how-does-a-hydrogen-fuel-cell-workhttps://en.wikipedia.org/wiki/Platinum
This setup is common in proton exchange membrane fuel cells, or PEM fuel cells, used in vehicles and portable power systems. Platinum makes the reactions fast and efficient, often reaching 40 to 60 percent electrical efficiency. It is especially good at handling the oxygen reduction at the cathode and hydrogen oxidation at the anode.https://www.pi-kem.co.uk/research-areas/hydrogen-production-and-fuel-cell-technologyhttps://energyinstitute.jhu.edu/the-platinum-problem/
One reason platinum works so well is its ability to bind hydrogen and oxygen just right, not too strong or too weak. Recent studies show that tiny platinum particles, under 2 nanometers, can form surface hydrides during operation. These hydrides tweak the binding energy of hydrogen, boosting activity for both hydrogen evolution and oxidation reactions. Smaller particles show even better results over time.https://www.nature.com/articles/s41467-025-65122-2
But platinum has downsides. It is rare and expensive, which drives up fuel cell costs and limits widespread use in things like trucks or buses. A single fuel cell stack might need several grams of platinum, making hydrogen vehicles pricier than battery ones right now. Researchers note that platinum can also oxidize during use, affecting performance.https://www.youtube.com/watch?v=jf5dGuuoN7ohttps://www.avl.com/en/blog/3d-simulation-a-pem-fuel-cell-air-start-scenario-including-degradation
To cut costs, scientists are seeking alternatives. Some experiments use iron, nitrogen, and carbon mixes that mimic platinum’s effects without the high price. Others explore high-entropy alloys or hybrid layers with far less platinum, potentially reducing it by 80 to 90 percent. AI tools now help predict new materials that could match or beat platinum.https://energyinstitute.jhu.edu/the-platinum-problem/
Platinum remains the top choice today for reliable fuel cells in green energy, from vehicles to power systems. Ongoing work aims to make it last longer and use less of it.
Sources
https://en.wikipedia.org/wiki/Platinum
https://www.nature.com/articles/s41467-025-65122-2
https://www.youtube.com/watch?v=jf5dGuuoN7o
https://energyinstitute.jhu.edu/the-platinum-problem/
https://www.tycorun.com/blogs/news/how-does-a-hydrogen-fuel-cell-work
https://www.pi-kem.co.uk/research-areas/hydrogen-production-and-fuel-cell-technology
https://www.avl.com/en/blog/3d-simulation-a-pem-fuel-cell-air-start-scenario-including-degradation