Efficient Bicarbonate Electrolyzer with a Forward-Bias Bipolar Membrane.
Mingyi Wang1, Wenke Lian1, Wenrui Zhang1
1School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, P. R. China.
ACS Applied Materials & Interfaces
|April 7, 2026
Summary
Direct electrolysis of captured carbon dioxide (CO2) in bicarbonate solutions is enhanced using a forward-bias bipolar membrane (fBPM). This method improves CO2 conversion efficiency and viability for integrated capture and electrochemical conversion.
Area of Science:
- Electrochemistry
- Materials Science
- Chemical Engineering
Background:
- Direct electrolysis of CO2-captured bicarbonate solutions is a promising CO2 valorization strategy.
- Existing methods often suffer from low energy efficiency due to proton-driven CO2 release and hydrogen evolution.
Purpose of the Study:
- To demonstrate a novel bicarbonate electrolyzer utilizing a forward-bias bipolar membrane (fBPM).
- To decouple local CO2 release from proton flux for improved electrochemical performance.
Main Methods:
- Fabrication and testing of a bicarbonate electrolyzer employing an fBPM.
- Utilizing operando Raman spectroscopy to analyze the cathode-membrane microenvironment.
- Conducting system-level energy analysis for CO2 conversion.
Main Results:
- The fBPM cell achieved a high CO partial current density of 167.1 mA cm-2 at 4.44 V.
- CO Faradaic efficiencies reached up to 71% at 100 mA cm-2.
- The fBPM maintained an alkaline cathode-membrane microenvironment, enhancing local CO2 availability.
Conclusions:
- The fBPM-based electrolyzer offers superior performance compared to other configurations.
- This approach presents a viable method for integrated CO2 capture and electrochemical conversion with an energy cost of 36.7 GJ/tonne CO.
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