Adsorption of carbon dioxide on aminosilane-modified mesoporous silica

Aminosilane-modified mesoporous silica was prepared by grafting various aminosilanes on mesoporous silica, SBA-15, and the applicability as a novel adsorbent for CO2 capture and separation from flue gases was examined. Pore walls of SBA-15 were modified uniformly with aminosilanes by grafting and relatively high surface area and uniform pore size were retained. Adsorption capacities Of CO2 in the presence of water were compared with those in the absence of water by a flow method. Adsorption capacities of aminosilane-modified SBA-15 were comparable in the presence and absence of water vapor. In particular, the adsorption capacity of (3-trimethoxysilylpropyl)diethylenetriamine SBA-15 reached 1.2 mmol (.) g(-1) in the presence of water vapor at 333 K, which is comparable to the adsorption capacity of zeolite Na-Y in the absence of water vapor. In addition, these adsorbents were completely regenerated by heating to 423 K in a He flow.