Electrochemical CO2 conversion with a flow-through copper hollow fibre: A process parameter evaluation

Incentive for the development of techniques that utilize CO2 as a feedstock, is provided by emission of fossil-derived carbon dioxide (CO2) and its corresponding accumulation in the atmosphere. The dissertation focusses on a method to convert CO2 in carbon monoxide (CO), while utilizing renewable electricity to drive the reaction. Contrary to the commonly used flat-sheet electrodes where CO2 is flown past the electrode, the research presented in the dissertation utilizes a tubular, copper gas diffusion electrode, with CO2 flown through the porous wall of the electrode. The dissertation studies the behaviour of these so-called copper hollow fibre electrodes operated in flow-through configuration in different reaction conditions.

The outline of the dissertation is as follows. Chapter 1 puts the work presented in this dissertation in a wider perspective, and introduces the main reactions and parameters involved in electrochemical CO2 conversion. The subsequent chapter, Chapter 2, investigates the consequences of feeding a mixture of CO and CO2 to copper hollow fibre electrodes, while aiming for electrochemical CO2 conversion. Chapter 3 studies the effect of the aqueous electrolyte identity on the performance of copper hollow fibre electrodes. The following chapter, Chapter 4, investigates the fibre’s ability to convert CO2 in ethylene rather than CO. The final chapter of the dissertation, Chapter 5, reflects upon the research presented in the dissertation. The dissertation concludes that if the copper hollow fibres are to be used as CO2 to CO electrocatalyst, the fibre’s surface characteristics and its operating conditions are to be changed such that H2 and formate production are limited, while CO production is allowed to occur.