Developing a Suitable Anion Exchange Layer Structure for Pure–Water Fed Bipolar Membrane CO2 Electrolysis

Lorenz H, Roubicek N, Thiele S, van Pham C (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Energy & Environmental Materials Wiley

DOI: 10.1002/eem2.70338

Abstract

Anion exchange membrane-based CO2 electrolyzers powered by renewable energy provide a promising pathway for a sustainable CO2-to-CO conversion. However, they suffer from CO2 crossover via the formation of (bi)carbonates, limiting carbon utilization to 50%, and electrolyte-driven salt precipitation, which shortens device lifetime. A forward-biased bipolar membrane addresses these issues by operating with pure water and regenerating CO2 at the bipolar junction. Nevertheless, instability of the bipolar interface, lower faradaic efficiency, and high cell potential remain open challenges. Here, we present a bipolar membrane incorporating a porous anion exchange layer to facilitate CO2 release out of the bipolar junction. Two bipolar membrane configurations are compared with a porous or dense anion exchange layer deposited either onto a silver-based gas diffusion electrode or onto the cation exchange membrane. Porous anion exchange layer-coated gas diffusion electrodes achieved enhanced stability, lower cell potentials, and partial current densities for CO up to 214 mA cm−2 at 3.25 V. Implementation of this bipolar membrane architecture reduces CO2 crossover by at least 80% compared with an anion exchange membrane-based electrolyzer, although CO2 losses to the anode persist, highlighting the need for further optimization. These findings establish porous anion exchange layer-coated gas diffusion electrodes as a promising strategy for advancing bipolar membrane CO2 electrolysis.

Involved external institutions

Forschungszentrum Jülich / Research Centre Jülich (FZJ) DE Germany (DE)

How to cite

APA:

Lorenz, H., Roubicek, N., Thiele, S., & van Pham, C. (2026). Developing a Suitable Anion Exchange Layer Structure for Pure–Water Fed Bipolar Membrane CO2 Electrolysis. Energy & Environmental Materials. https://doi.org/10.1002/eem2.70338

MLA:

Lorenz, Henning, et al. "Developing a Suitable Anion Exchange Layer Structure for Pure–Water Fed Bipolar Membrane CO2 Electrolysis." Energy & Environmental Materials (2026).

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