Electrochemical low‑concentration CO₂ capture and conversion: from catalyst design to electrolyzer engineering
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Schematic overview of electrochemical low-concentration CO2 capture and conversion, highlighting integrated single and dual electrolytic cell capture–conversion systems, direct dilute CO2 electrolysis through local CO2 enrichment and impurity-tolerant catalyst design, and electrolyzer engineering strategies involving gas diffusion layers, flow-field design, and operating-condition optimization.
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Electrochemical CO2 reduction uses renewable electricity to convert CO2 into value-added fuels and chemicals, offering a promising route for carbon recycling. However, most current studies rely on high-purity CO2 feeds, while practical carbon sources such as industrial flue gas and air contain dilute CO2 together with impurities including O2, SOx, and NOx. Low CO2 concentrations limit mass transport and promote the competing hydrogen evolution reaction, while impurities may trigger side reactions or deactivate catalytic sites. A team of scientists has reviewed recent progress in the electrochemical capture and conversion of dilute CO2, outlining strategies to bring CO2 electrolysis closer to practical carbon sources. Their work is published in the journal Industrial Chemistry & Materials on July 15, 2026.
“One of the key challenges is to maintain sufficient CO2 availability at the active sites under dilute CO2 while minimizing the effects of competing reactions and impurities,” explains Ying Wang, a professor at The Chinese University of Hong Kong.
The researchers highlight two main approaches for utilizing dilute CO2. The first is integrated CO2 capture and conversion. In single electrolytic cell systems, captured carbon species are directly converted within the same device, while dual electrolytic cell systems separate CO2 capture from electrochemical conversion, allowing the two processes to be optimized independently.
The second route is the direct electrolysis of dilute CO2, which avoids a separate capture step but faces greater challenges in CO2 transport and impurity tolerance. Strategies such as porous catalyst structures, CO2-affinity functional groups, and wettability regulation can increase the local CO2 concentration near active sites and stabilize the gas-liquid-solid reaction interface.
Impurities in realistic gas streams present an additional challenge. O2 can compete for electrons through the oxygen reduction reaction, SOx may cause irreversible poisoning of catalytic sites, and NOx can undergo competing reduction reactions. Developing catalysts and interfaces that favor CO2 transport and conversion while suppressing these unwanted pathways is therefore important for direct flue-gas electrolysis.
The review also emphasizes that catalyst development alone is not sufficient. Gas diffusion layers, flow-field design, pressure, temperature, humidity, and electrolyte composition all influence reactant transport, product selectivity, and long-term stability.
“Dilute CO2 electrolysis is not simply a catalyst problem, but a system-level challenge,” says Professor Wang. “Catalyst design and electrolyzer engineering need to be considered together to achieve efficient and stable operation under realistic conditions.”
Looking ahead, the researchers identify several priorities, including multifunctional catalysts for CO2 enrichment and impurity tolerance, a better understanding of catalyst deactivation under mixed contaminants, operando measurement of local CO2 concentrations, and improved mass-transfer uniformity during electrolyzer scale-up. These advances could help enable selective, durable, and scalable electrochemical conversion of low-concentration CO2 from practical carbon sources.
The research team includes Birou Huang, Renzhong Zhang, Qian Lu, Weixing Wu, Zhuohan Chen, and Ying Wang from The Chinese University of Hong Kong; and Pratahdeep Gogoi and Yuguang C. Li from the University at Buffalo, The State University of New York.
This research is funded by the Research Grants Council of the Hong Kong Special Administrative Region and the 1+1+1 CUHK-CUHK(SZ)-GDSTC Joint Collaboration Fund.
DOI Link:
https://doi.org/10.1039/d6im00201c
About Industrial Chemistry & Materials
Industrial Chemistry & Materials is a peer-reviewed interdisciplinary academic journal published by Royal Society of Chemistry (RSC) with APCs currently waived. ICM publishes significant innovative research and major technological breakthroughs in all aspects of industrial chemistry and materials, especially the important innovation of the low-carbon chemical industry, energy, and functional materials. Check out the latest ICM news on the blog.
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Industrial Chemistry and Materials
Article Title
Electrochemical low-concentration CO2 capture and conversion: from catalyst design to electrolyzer engineering
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