Differential pressure CO2 electrolysis opens the way for direct coupling to industrial processes

Pressurized electrochemical carbon dioxide reduction (CO2R) offers a pathway to enhance selectivity, current density, and process integration. While elevated pressures improve CO2R performance, differential pressure operation above 10 bar between cathode and anode remains underexplored. This study introduces an innovative test facility and a continuous high-pressure reactor with a zero-gap architecture, enabling gaseous CO2 electrolysis at a differential pressure of 40 bar(g). Using a bipolar membrane electrode assembly eliminates the need for CO2 humidification, and using ultrapure water as the sole proton source creates a salt-free environment without acid or base additives. This setup achieved a Faraday efficiency for CO of 81% at 500 mA cm-2, efficient CO2R with a CO2 excess (λCO2) below 4, and single-pass conversion rates up to 26% at 40 bar(g). The pressurized CO2R outlet streams have low CO2 content, enabling direct integration into downstream chemical processes. This marks a key advancement toward scalable, energy-efficient industrial CO2 electrolysis systems.