Hidden parameters for electrochemical carbon dioxide reduction in zero-gap electrolyzers

Cell Reports Physical Science, vol. 3, pp. 100825

Abstract

The electrochemical reduction of CO2 from flue gas or direct air capture to relevant syngas mixtures is a promising route toward mitigation of environmental pollution and production of bulk chemicals and fuels. Among the different cell types, gas-fed zero-gap electrolyzers are promising as energy-efficient and scalable devices. We herein investigate the influence of operational parameters related to cathode water management, such as cell orientation, gas humidification, and cathode compression onto CO2R. By a stepwise optimization of our not yet fully optimized electrolyzer, stability could be improved by a factor of 3 up to 10 h at 3 V and 300 mA cm−2. Faradic efficiency for CO after 2 h of electrolysis was increased from 14% to over 60%. Controlling the water management is a key parameter as high water input leads to flooding of the electrodes, whereas lower values decrease the performance of the anion exchange membrane and reduce catalyst wetting.

Authors 7

1. Lucas Hoof

   Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT

   Affiliation as printed

   Fraunhofer Institute for Environmental, Safety and Energy Technology, UMSICHT, 46047 Oberhausen, Germany

2. Niklas Thissen

   Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT

   Affiliation as printed

   Fraunhofer Institute for Environmental, Safety and Energy Technology, UMSICHT, 46047 Oberhausen, Germany

3. Kevinjeorjios Pellumbi

   Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT · Ruhr University Bochum

   Affiliation as printed

   Fraunhofer Institute for Environmental, Safety and Energy Technology, UMSICHT, 46047 Oberhausen, Germany

   Inorganic Chemistry I, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany

4. Kai junge Puring

   Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT

   Affiliation as printed

   Fraunhofer Institute for Environmental, Safety and Energy Technology, UMSICHT, 46047 Oberhausen, Germany

5. Daniel Siegmund

   Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT · Ruhr University Bochum

   Affiliation as printed

   Fraunhofer Institute for Environmental, Safety and Energy Technology, UMSICHT, 46047 Oberhausen, Germany

   Inorganic Chemistry I, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany

6. Anna K. Mechler Aachen Electrochemical Reaction Engineering

   RWTH Aachen University

   Affiliation as printed

   Electrochemical Reaction Engineering, RWTH Aachen University, 52074 Aachen, Germany

7. Ulf‐Peter Apfel corresponding

   Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT · Ruhr University Bochum

   Affiliation as printed

   Fraunhofer Institute for Environmental, Safety and Energy Technology, UMSICHT, 46047 Oberhausen, Germany

   Inorganic Chemistry I, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany