Recent progress on integrated CO2 capture and electrochemical upgrading

Abstract

Technologies for CO2 capture and utilization (CCU) are crucial for combating ever-increasing climate change. While the electrochemical conversion of captured CO2 has flourished in the past few years, CO2 capturing techniques are relatively mature. Typical capturing media include alkaline and amine solutions, as well as porous nanomaterials. Scaling CCU requires efficient integration of initial capture and subsequent conversion processes into one device, which is typically referred to as an integrated process. This approach has witnessed notable progress in recent years, which motivates this timely and comprehensive review. We first compare the economic aspects of separate and integrated CCU systems. Then, we discuss the separate CCU approaches that have traditionally been employed and expound on the motivations to develop an integrated system. We focus specifically on two integrated CCU approaches – direct electrolysis of capture solutions and the adoption of bifunctional porous electrodes. We also introduce the working mechanism of each approach and the latest developments, along with a comprehensive discussion on remaining challenges. To conclude, we provide an overall evaluation and outlook on advancing this integrated approach for CCU.