A research team at UNIST has introduced a new electrochemical system that efficiently converts carbon dioxide (CO2), a major greenhouse gas, into high-value chemicals like formic acid. This system slashes energy consumption by nearly 75 % and delivers production rates three times higher than current methods.
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Led by Professor Seungho Cho from the Department of Materials Science and Engineering, in collaboration with Professors Youngkook Kwon and Jae Sung Lee from the School of Energy and Chemical Engineering, the team has developed an ultra-low voltage process for converting CO2 into formic acid.
Unlike traditional systems that depend on the oxygen evolution reaction (OER), which accounts for 70–90 % of the total energy use and pushes operating voltages up to 2 V, this new method replaces OER with a formaldehyde oxidation reaction (FOR). As a result, the system operates at just 0.5 V while maintaining impressive Faradaic efficiencies: 96.1 % at the cathode and 82.1 % at the anode.
This low-voltage setup significantly cuts power requirements while boosting output. The process achieved a formic acid production rate of 0.39 mmol/cm2·h, nearly tripling the performance of previous technologies.
By pairing CO2 reduction with formaldehyde oxidation, which itself generates formic acid rather than oxygen, the overall energy efficiency is substantially improved.
A key component of this system is a specially engineered copper-silver (CuxAg10-x) composite catalyst. Designed for long-term stability and efficiency, this material resists the rapid performance decline seen in many conventional catalysts, making it well-suited for scalable, sustainable applications.
Beyond CO2 conversion, the research team demonstrated the catalyst's potential in other eco-friendly chemical processes. They successfully integrated formaldehyde oxidation with nitrate reduction, oxygen reduction, and hydrogen evolution reactions to produce ammonia, hydrogen peroxide, and hydrogen, all without generating emissions or relying on external electricity.
This technology addresses the main inefficiency in CO2 conversion and makes the most of limited electric energy. Its versatility opens new possibilities for sustainable chemical manufacturing and environmental protection.
Seungho Cho, Professor, Department of Materials Science and Engineering, UNIST
Journal Reference:
Kim, H., et al. (2025) Energy-Efficient Dual Formate Electrosynthesis via Coupled Formaldehyde Oxidation and CO2 Reduction at Ultra-Low Cell Voltage. Angewandte Chemie International. DOI:10.1002/anie.202516232. https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202516232.