ETH Zurich unveils single-atom indium catalyst revolutionising CO2 to methanol conversion

Researchers at ETH Zurich report a step change in catalysts for producing methanol from carbon dioxide and hydrogen, demonstrating that atomically dispersed indium on a hafnium oxide support markedly improves efficiency and mechanistic clarity compared with nanoparticle-based materials. According to the paper in Nature Nanotechnology published 2 March 2026, the team engineered a single‑atom architecture in which every indium atom functions as an active site, enabling superior CO2 hydrogenation performance under temperatures up to about 300°C and pressures approaching 50 bar.

Methanol occupies a central role in industrial decarbonisation as a versatile feedstock for polymers, chemicals and fuels. “Methanol is a universal precursor for the production of a wide range of chemicals and materials, such as plastics – the Swiss army knife of chemistry, so to speak,” Javier Pérez‑Ramírez, Professor of Catalysis Engineering at ETH Zurich, told the authors. If electrolytic hydrogen and renewable energy are employed, CO2‑to‑methanol routes can in principle displace fossil feedstocks and close a carbon loop by treating atmospheric CO2 as a raw material rather than a waste stream.

The ETH group attributes the performance gains to two linked advances: maximising the utilisation of each metal atom by isolating indium sites, and designing a hafnia matrix that both anchors those atoms and endows them with a reactive electronic environment. The researchers developed synthesis routes , including rapid quench of flame‑synthesised precursors at 2,000–3,000°C , that favour surface‑bound isolated indium rather than the conventional metal aggregates found in typical catalysts. The result, the authors say, is a catalyst whose active sites can be probed without the confounding signals that arise from bulk atoms hidden inside nanoparticles.

“In our study, we show that isolated indium atoms on hafnium oxide allow more efficient CO2‑based methanol synthesis than indium in the form of nanoparticles containing large numbers of atoms,” the paper states, signalling both a materials and an analytical advantage: single‑atom systems both reduce precious‑metal loading and simplify mechanistic interpretation.

The ETH findings sit within a growing body of work showing that atomic dispersion and support chemistry are critical levers for CO2 hydrogenation. Computational and experimental studies have demonstrated that single atoms of platinum, palladium, nickel and rhodium on indium oxide surfaces alter reaction pathways and selectivity compared with clustered metals, while bulk‑doped Pt/In2O3 designs predicted by density functional theory and microkinetic modelling have suggested routes to boost activity without sacrificing methanol yields. Other teams have stabilised single‑atom copper sites inside metal‑organic frameworks by engineering alkali‑decorated microenvironments, producing robust activity at elevated temperatures.

Complementary experimental research has explored promotion strategies and particle‑size effects on indium‑based catalysts: cobalt promotion of In2O3 improves reducibility and methanol productivity relative to nickel promotion, and sub‑1 wt% loadings of rhenium on In2O3 can produce atomically dispersed, positively charged species that enhance hydrogen activation and selectivity under high‑temperature conditions. Separately, pairing indium‑based oxide semiconductors with palladium nanoparticles has been shown to raise reaction rates and methanol selectivity dramatically, highlighting the importance of metal–oxide junctions and electronic structure in catalyst design.

For industrial practitioners, the ETH work carries practical implications. Single‑atom catalysts promise higher metal atom economy , a crucial consideration when rare or costly elements are involved , and, by maintaining atomic dispersion on a thermally robust hafnia support, they may withstand the demanding temperatures and pressures typical of commercial methanol synthesis. The paper also underscores the value of interdisciplinary research and shared infrastructure: Pérez‑Ramírez is director of the Swiss National Centre of Competence in Research (NCCR) Catalysis, which brings together dozens of groups to accelerate scalable, lower‑carbon chemical processes. “The development of the methanol catalyst and the detailed analysis of the mechanism would not have been possible without this interdisciplinary expertise,” he said.

Challenges remain before single‑atom indium catalysts can be deployed at scale. Long‑term stability under continuous operation, costed synthesis at industrial volumes, and integration with low‑carbon hydrogen supply chains must be demonstrated. Moreover, comparative assessments against alternative single‑atom and promoted oxide systems will be necessary to identify the most effective and durable formulations for specific plant parameters.

Nonetheless, the ETH Zurich study reinforces a broader shift in catalyst strategy: moving from empirically discovered nanoparticle mixtures to deliberately designed, atom‑level active sites supported by tailored matrices. For companies pursuing fossil‑free routes to base chemicals, that shift offers a pathway to reduce material intensity, sharpen mechanistic understanding and potentially lower the energy and emissions cost of producing methanol from CO2.