Design and Validation of a High-Pressure CO₂ Electrocatalysis System

High-pressure carbon dioxide (CO₂) electrocatalysis is a promising pathway for reducing greenhouse gas emissions while producing valuable fuels and chemicals. Elevated pressures improve CO₂ solubility and reaction rates, yet most existing systems are limited to ambient conditions. Few setups support high-pressure CO₂ electrocatalysis with liquid diffusion cathodes, creating a need for new infrastructure. The objective of this work was to design and assemble a system capable of enabling high-pressure CO₂ electrocatalysis. The setup integrates a custom-designed stainless steel pressure vessel rated above 12 bar, chemically inert PTFE tubing, high-pressure compatible pumps, and a back-pressure regulator to safely return products to atmospheric conditions for gas chromatography (GC) analysis. Stress calculations confirmed high safety margins, with factors of safety exceeding 40 in some components. To minimize cost and maintain flexibility, the vessel was custom-fabricated, and soft tubing was incorporated to allow for different system configurations. These design choices ensured durability while avoiding contamination that could compromise electrochemical measurements. A simpler system modelling solely the anode portion was first validated with water and nitrogen, successfully operating at 5 bar, limited by pump capacity, but designed to accommodate higher pressure-rated pumps. Safety and robustness were demonstrated, and the setup maintained stability while remaining adaptable for future modifications. While the pressure vessel is less flexible due to high-pressure constraints, the modularity of other components provides significant room for customization and scaling. This work establishes a practical foundation for future high-pressure CO₂ electrocatalysis studies. By enabling experiments at industrially relevant conditions, the system supports research toward improved efficiency, selectivity, and scalability, moving closer to making CO₂ electrocatalysis a viable approach for carbon mitigation and renewable fuel production.