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 (λ_CO2) 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.