An Efficient Amine-Modified Silica Aerogel Sorbent for Co2 Capture Enhancement : Facile Synthesis, Adsorption Mechanism and Kinetics

Developing a cost-effective and high-efficiency solid sorbent for CO 2 low temperature capture is current research focus. In this work, amine-modified silica (SiO 2 ) aerogels were synthesized by grafting with 3-(Aminopropyl) triethoxysilane (APTES) via a simple ambient pressure drying process, and verified as efficient sorbents for CO 2 capture. The effects of sol pH value and APTES concentration on the microstructure and CO 2 adsorption property of as-prepared amine-modified silica aerogels (AMSAs) were investigated in detail. A double exponential model was proposed to reveal the kinetics adsorption mechanism of the AMSAs for the first time. Results demonstrate that the AMSAs exhibited a high CO 2 adsorption ability of 3.37 mmol∙g -1 at 70 o C, and maintained 87.6 % of the original capacity after 10 adsorption-desorption cycles, indicative of long cycle stability of the sorbent. Moreover, the kinetic adsorption behavior could be well simulated by the double exponential model, and the CO 2 diffusion process was the speed-controlling step in the whole CO 2 adsorption process. The diffusion active energy of AMSAs on CO 2 capture was also calculated. This facile and environmental-friendly synthesis method may provide a novel reference for enhanced CO 2 capture sorbents