Electrochemical CO<sub>2</sub> reduction integrated with membrane/adsorption‐based CO<sub>2</sub> capture in gas‐diffusion electrodes and electrolytes
Hesamoddin Rabiee, Penghui Yan, Hao Wang, Zhonghua Zhu, Lei Ge
Abstract
Abstract Electrochemical CO 2 reduction reaction (CO 2 RR) has attracted much attention in the last decade, owing to its unique advantages such as operation at ambient conditions, coupling with renewable electricity, and producing a wide range of products and commodities. The majority of CO 2 RR studies are focused on pure CO 2 as feed, while in real CO 2 waste streams, such as flue gas or biogas, CO 2 concentration does not exceed 40%. Therefore, the economic feasibility of CO 2 RR and its carbon footprint are greatly limited by the CO 2 purification steps before electrolysis ($70–100 per ton of CO 2 for CO 2 /N 2 separation). In recent years, studies have exhibited the importance of this matter by integrating CO 2 capture and electroreduction in a single unit. Mostly, CO 2 capture solutions as electrolytes have been under attention, and promising results have been achieved to significantly improve the overall economy of CO 2 RR. The focus on CO 2 capture‐electroreduction integration can go beyond the solution/electrolyte‐based CO 2 capture (e.g., amine solutions and ionic liquids) and other processes such as solid adsorption and membrane‐based processes, as more efficient options, can be potentially integrated with CO 2 electroreduction in the gas‐diffusion electrode design. This article aims to review the recent efforts in integrating capture and electroreduction of CO 2 and provides new perspectives in material selection and electrode design for membrane‐ and adsorption‐based CO 2 capture‐reduction integration, in addition to the analysis of the economic feasibility of this integration.