New Approach to Enhance CO₂ Capture of “Molecular Basket” Sorbent by Using 3-Aminopropyltriethoxysilane to Reshape Fumed Silica Support

Abstract

Here we report a new approach to enhance CO 2 capture and separation over a solid molecular basket sorbent by reorganizing the aggregation of fumed silica (FS) support particles with the addition of 3-aminopropyltriethoxysilane (APTES). After APTES modification, although the surface area of fumed silica decreased, the total pore volume increased significantly, more than 2 times larger than that of fumed silica itself. Compared to fumed silica supported PEI sorbent, the 30PEI/APTES-FS sorbent can achieve a CO 2 capacity as high as 130.4 mg-CO 2 /g-sorb, a 44% increase from 90.4 mg-CO 2 /g-sorb over 30PEI/FS. The amine efficiency of PEI for CO 2 sorption was also improved by over 25%. Furthermore, both the CO 2 sorption and desorption kinetics were greatly enhanced by 1.23 and 1.61 times, respectively, compared to the PEI/FS sorbent without APTES modification. In addition, the stability and regenerability of PEI/FS sorbent was also greatly improved.

CO2 Capture and Utilization Editorial

“…The combined effect of PEI and a silane on silica gel was explored, reaching better results than PEI itself. 12 Furthermore, the group of Prof. Sayari has covalently immobilized PEI to porous Al-silica to overcome the disadvantages of the impregnation technique, directing his efforts to investigate the oxidative stability of the materials. 13 Measuring adsorption kinetics on amine-loaded sorbents is crucial not only for material development purposes but also for reactor design and process development.…”

“…The most commonly impregnated compound is polyethylenimine (PEI). The combined effect of PEI and a silane on silica gel was explored, reaching better results than PEI itself . Furthermore, the group of Prof. Sayari has covalently immobilized PEI to porous Al-silica to overcome the disadvantages of the impregnation technique, directing his efforts to investigate the oxidative stability of the materials …”

Carbon Capture From Flue Gas and the Atmosphere: A Perspective

“…The formation of C O and −CH N-species is a main reason for the air degradation of amine sorbents (Ahmadalinezhad and Sayari, 2014). To improve the regeneration and long-term stability of PEI-based sorbents, a two-step synthesis strategy involving support modification followed by PEI loading has been proposed and studied (Choi et al, 2016;Jeon et al, 2018;Min et al, 2018a;Min et al, 2018b;Xu et al, 2018;Kim et al, 2019;Wang et al, 2020), which have been summarized and elaborated in our recent book chapter (Wang and Song, 2019).…”

Recent progress on (3-Aminopropyl)triethoxysilane (APTES) functionalized-adsorbent for CO2 capture

“…Furthermore, the amount of amine loading also could significantly impact the CO2 adsorption of the adsorbents. For instance, a study was conducted by Wang and co-workers on CO2 capture of fumed silica (FS) with no definite structure and tiny mesopores particles that might suffer an agglomeration issue [16]. As APTES covers the surface of silica support, the total pore volume and surface area were declined progressively, but still significantly higher than that of the pure FS.…”