Progress in Amine-Functionalized Silica for CO2 Capture: Important Roles of Support and Amine Structure

In the past decades, huge developments in rational design, synthesis, and application of solid amine CO2 adsorbents have been reported. Since the reports on polyethylenimine impregnated silica adsorbents, there has been tremendous growth in this area along with the increase of supported amine adsorbent related publications. Owing to high adsorption capacity, a facile synthesis procedure and low cost, amine-functionalized silica adsorbents demonstrate great promise for CO2 capture technologies. To push their industrial application forward, their stability must be improved further to mitigate acidic impurities and CO2, O2, and thermal-induced deactivation. Furthermore, fundamental understanding of the relationship between amine / support structure and adsorption performance is needed to guide the design of stable amine silica adsorbents. This review summarizes recent research that mainly focuses on important roles of support and amine structure in CO2 adsorption performance and improved stability. The recent progress in promising reactor design for solid amine adsorbents is discussed to provide insights on developing the continuous CO2 capture process for separating CO2 from flue gas and ambient air.