Technology that converts carbon dioxide (CO₂) into fuels and plastic feedstocks using electricity is gaining attention as a core technology in the era of carbon neutrality. In particular, ethylene and ethanol are high-value materials widely used in the production of plastics, fuels, and chemical products, but until now, the only metal that has effectively produced them has essentially been copper (Cu). Through this study, Korean researchers have revealed the limitations of existing catalyst theories that have explained this principle.

KAIST (President Kwang Hyung Lee) announced on the 21st of May that a research team led by Professor Jihun Oh of the Department of Materials Science and Engineering, through joint research with Professor Stefan Ringe’s team from the Department of Chemistry at Korea University (President Dongwon Kim), has identified a new operating principle of the electrochemical CO₂ reduction reaction (CO₂ reduction reaction, a reaction that uses electricity to convert carbon dioxide into other chemical substances).

The research team fabricated alloy catalysts made by mixing gold (Au), silver (Ag), and palladium (Pd), and analyzed what substances these catalysts convert CO₂ into.

Existing catalyst theories have predicted that if the “d-band center” (an indicator of the electronic reactivity of a catalyst) and “work function” (the energy required for a metal to release electrons outward), which indicate the reactivity of electrons on the catalyst surface, are similar to those of copper, then the catalyst should be able to produce multi-carbon (C2+) compounds such as ethylene and ethanol like copper does.

Using a co-sputtering process (a technique that simultaneously deposits multiple metals as thin films to create a new alloy with a desired ratio), the research team precisely fabricated a ternary alloy (AuAgPd, an alloy made by mixing three metals: gold, silver, and palladium) with electronic properties very similar to those of copper.

However, the actual experimental results were different. This alloy produced simple products such as carbon monoxide (CO), but it did not produce complex multi-carbon compounds such as ethylene or ethanol at all. This means that complex CO₂ conversion reactions are difficult to explain using only the electronic properties of catalysts. In other words, the study confirmed that how atoms are arranged on the catalyst surface also has an important effect on reaction performance.

The research team expects that this study will provide important clues for developing next-generation high-efficiency catalysts that can replace copper in the future. In particular, the study is significant in that it presents a new direction showing the need for precise catalyst design strategies that go beyond existing designs centered only on simple electronic structure and also consider atomic arrangement.

Professor Jihun Oh stated, “This study shows that existing catalyst theories alone are insufficient to fully explain complex multistep carbon conversion reactions,” adding, “In the future, a new catalyst design strategy that considers both electronic properties and local atomic arrangement, meaning how atoms are arranged on the catalyst surface, will be necessary.”

This paper, with KAIST Dr. Beomil Kim, doctoral student Suneon Wang, and Korea University Dr. Seungchang Han as first authors, was published in the May 2026 issue of the international journal Nature Catalysis.
※ Paper title: “Peaks and pitfalls of electrocatalytic CO₂ reduction descriptor models,” DOI: 10.1038/s41929-026-01526-7
※ Lead authors: Beomil Kim (KAIST, first author), Seungchang Han (Korea University, first author), Suneon Wang (KAIST, first author), Jihun Oh (KAIST, corresponding author), Stefan Ringe (Korea University, corresponding author)

This research was supported by the Nano and Material Technology Development Program, the Top-Tier Research Institution Collaboration Platform and Joint Research Support Program, and the Individual Research Program of the National Research Foundation of Korea funded by the Ministry of Science and ICT, as well as by the National Supercomputing Center at the Korea Institute of Science and Technology Information (KISTI).