New Plasmonic Photocatalyst Reduces Hydrogen Production Costs

American chemists have developed a plasmonic photocatalyst based on rhodium and copper, enabling the extraction of hydrogen from methane at a relatively low temperature of 450 degrees Celsius. This innovation is expected to lower energy and fuel costs for hydrogen production, making the process more sustainable, as detailed in a paper published in Nature Catalysis.

“Steam methane reforming accounts for roughly half of the hydrogen produced globally, but it traditionally requires very high temperatures, leading to significant energy consumption and greenhouse gas emissions,” the researchers explained. The newly developed photocatalyst aims to make hydrogen production greener by lowering the required temperature and associated emissions.

The catalyst, developed by a team led by Professor Naomi Halas at Rice University, consists of nanoparticles made of rhodium and copper, which are deposited on a substrate of aluminium and magnesium oxides. These nanoparticles are positioned precisely to generate plasmons—special collective oscillations of electrons—when exposed to light. These plasmons cause the nanoparticles to heat the surrounding environment and promote electron activity, effectively aiding the reaction.

Two years ago, scientists demonstrated that plasmons could split ammonia into nitrogen and hydrogen at very low temperatures. Building on that insight, the team found that similar nanoparticles, composed of 97% copper and 3% rhodium, could be used to split methane into hydrogen and carbon monoxide at about 450 degrees Celsius. These catalysts have shown stability for tens of hours, offering promise for industrial-scale hydrogen production.

Chemists believe that this development could significantly lower the cost of hydrogen production and reduce its environmental impact, offering a greener alternative for a crucial industrial process.