Researchers have developed a low-cost catalyst for green hydrogen production that performed within 50 millivolts of a ruthenium-based benchmark during oxygen evolution, yielding a potential alternative to catalysts made from scarce and expensive precious metals.

​The team created catalysts using nickel and iron oxides anchored to carbon nanofibers grown on a conductive two-dimensional material known as MXene. The study suggests the approach may help lower the cost of water electrolysis, a process that produces hydrogen without carbon emissions.

​Green hydrogen is made by splitting water into hydrogen and oxygen using electricity. Unlike conventional hydrogen production, which largely depends on fossil fuels, the process emits no carbon dioxide when powered by renewable energy. However, efficient water splitting requires electrocatalysts, which are typically made from costly metals such as platinum, ruthenium, and iridium.

​According to the researchers, about 96 percent of the world’s hydrogen is currently produced from fossil fuels. Producing one kilogram of conventional gray hydrogen releases roughly 22 pounds (10 kilograms) of carbon dioxide, while blue hydrogen produces about 13 pounds (6 kilograms).

​To curb reliance on precious metals, the researchers used Ti₃C₂Tₓ MXene as a conductive scaffold and grew carbon nanofibers directly on its surface through chemical vapor deposition. Iron or nickel oxide particles formed at the fiber tips, creating two catalyst materials: FeO-CNF@MX and NiO-CNF@MX.

​Microscopy and spectroscopy analyses established that the carbon nanofibers formed successfully across the MXene sheets while preserving the material’s layered structure. The nickel-based composite also produced a more graphitic and less defective carbon structure than the iron-derived version.

Source link