New catalysts offer dual hope for green hydrogen

Hydrogen is a vital feedstock for chemicals and fertilizers, and it’s gaining traction as a transportation fuel. But it is made today by heating natural gas to 1000°C, emitting 9–12 kg of carbon dioxide per kg of hydrogen. Then the gas needs to be compressed or liquefied for transport in specialized tanks.

To achieve a sustainable and practical hydrogen economy, researchers have been exploring the use of renewable bioethanol and methanol, liquid fuels from which hydrogen can be freed when needed. That process requires alcohol-to-hydrogen reforming catalysts. But the catalysts available currently require relatively high temperatures of 500 °C, create CO₂, and aren’t very durable.

Two new catalyst systems take aim at these problems. One catalyst splits ethanol to give hydrogen at 270 °C and produces valuable acetic acid instead of CO₂ (Science 2025, DOI: 10.1126/science.adt0682). Another shows record-high activity and stability for methane reforming at just 200 °C (Nature 2025, DOI: 10.1038/s41586-024-08483-w).

The advances come from teams led by Ding Ma at Peking University and Wu Zhou at the University of Chinese Academy of Sciences. The duo built on the methanol-reforming catalysts they previously made by studding molybdenum carbide (MoC) particles with platinum (Pt). The Pt/MoC catalysts convert carbon monoxide and water to CO₂ and hydrogen, a reaction known as the water-gas shift reaction.

Now, working with Graham J. Hutchings at Cardiff University and Jihan Zhou of Peking University, Ma and Zhou set out to eliminate CO₂ emissions from ethanol reforming. “For that, you need to eliminate the C–C bond breakage in ethanol, and the design of the catalyst is key,” Ma says.

The C–C bond breaks when ethanol adsorbs on metal catalyst clusters and forms carbon-metal bonds. The researchers found that adding a small amount of Pt on the MoC surface led to the formation of large Pt clusters that soaked up ethanol and cleaved the bonds. So they added an equal amount of iridium (Ir) and Pt. Ir interacts more strongly with MoC, and as a result, the Pt and Ir atoms disperse over the MoC surface—no noble metal clusters, no C–C bond breakage resulting in CO₂. Instead, the ethanol and water react to produce hydrogen and acetic acid.

But the hydrogen yield drops to a third that of conventional reforming, giving two hydrogen molecules per ethanol molecule, says Jose Maria Correa Bueno of the Federal University of São Carlos. “This raises concerns about its overall efficiency as a hydrogen production route.”

Ma argues that in addition to giving zero-carbon hydrogen if renewable ethanol is used, the production of acetic acid, an industrially important raw material, makes the process profitable at large scale. Various industries use over 15 million metric tons of acetic acid annually, and the researchers estimate that 1 ton of ethanol should give 1.3 tons of acetic acid.

In their work published in Nature, Ma, Zhou, and colleagues report on a methanol-reforming catalyst that is dramatically more stable and efficient than their previous one. This time, the researchers peppered molybdenum nitride (MoN) particles with Pt and added an inert lanthanum oxide layer to partially shield the MoN surface “so we can keep ultrahigh activity and get longevity.” With just a tiny amount of Pt (0.26% by weight), the catalyst produced 15.3 million hydrogen molecules for each Pt atom. The reaction ran at 200 °C, and the catalyst retained its high level of activity for more than 800 hours.

Matthias Beller, a catalysis expert at the University of Rostock, says that more research and improvements are needed to make the price and production of green methanol viable. Meanwhile, the main economic challenge of reforming ethanol for hydrogen and acetic acid will be the price of the bioethanol feedstock. Nonetheless, these two new catalytic reforming approaches are highly innovative, he says. “The obtained catalyst performances are truly impressive and might allow for practical industrial applications.”