An overview of porous silica immobilized amines for direct air CO capture

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 9; no. 48; pp. 27271 - 2733
• Main Authors: Cherevotan, Arjun, Raj, Jithu, Peter, Sebastian C
• Format: Journal Article
• Published: 14.12.2021
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d1ta05961k

An increased level of CO 2 in the atmosphere is identified as a threat to life on planet earth. Since hydrogenation of CO 2 back to fuel is identified as a major solution for both decreasing the emission and meeting the energy demands, the energy-efficient capture of CO 2 is recognized as an inevitably significant step. Small- and large-scale direct air capture (DAC) of CO 2 is a viable solution to address CO 2 discharge from industrial, automobile, and household activities (both point and mobile sources). The real challenge of DAC is to pick 400 molecules of CO 2 for capture from a million gas molecules in the atmosphere. Thus, in this report, we focus on reviewing the literature dealing with the chemical interaction between the sorbate (CO 2 ) and sorbent which is highly specific. Materials such as metal hydroxides and amine solutions are well discussed in other celebrated reviews and perspectives. Here we focus on inert porous silica immobilized amine materials emphasizing particularly on their advantages compared to other sorbent materials. Furthermore, amine functionalized novel silica materials such as bimodal porous silica and hierarchical silica are discussed highlighting the CO 2 capture mechanism, desorption, and sorbent-regeneration. Both O 2 and CO 2 -induced degradation pathways along with measures to retard sorbent degradation are presented. Finally, a brief overview of sustainability and future potential of amine-silica composite materials is presented to gain more insights. A comprehensive overview on porous silica immobilized amines as efficient materials for direct air CO 2 capture.