Zero-Gap Bipolar Membrane Electrolyzer for Carbon Dioxide Reduction Using Acid-Tolerant Molecular Electrocatalysts

Bhavin Siritanaratkul; Mark Forster; Francesca Greenwell; Preetam K Sharma; Eileen H Yu; Alexander J Cowan

doi:10.1021/jacs.1c13024

Zero-Gap Bipolar Membrane Electrolyzer for Carbon Dioxide Reduction Using Acid-Tolerant Molecular Electrocatalysts

J Am Chem Soc. 2022 May 4;144(17):7551-7556. doi: 10.1021/jacs.1c13024. Epub 2022 Apr 22.

Authors

Bhavin Siritanaratkul¹, Mark Forster¹, Francesca Greenwell¹, Preetam K Sharma², Eileen H Yu², Alexander J Cowan¹

Affiliations

¹ Stephenson Institute for Renewable Energy and the Department of Chemistry, University of Liverpool, Liverpool L69 7ZF, United Kingdom.
² Department of Chemical Engineering, Loughborough University, Loughborough LE11 3TU, United Kingdom.

Abstract

The scaling-up of electrochemical CO₂ reduction requires circumventing the CO₂ loss as carbonates under alkaline conditions. Zero-gap cell configurations with a reverse-bias bipolar membrane (BPM) represent a possible solution, but the catalyst layer in direct contact with the acidic environment of a BPM usually leads to H₂ evolution dominating. Here we show that using acid-tolerant Ni molecular electrocatalysts selective (>60%) CO₂ reduction can be achieved in a zero-gap BPM device using a pure water and CO₂ feed. At a higher current density (100 mA cm^-2), CO selectivity decreases, but was still >30%, due to reversible product inhibition. This study demonstrates the importance of developing acid-tolerant catalysts for use in large-scale CO₂ reduction devices.