Promoting the CO2 adsorption in the amine-containing SBA-15 by hydroxyl group

Novel CO2 capturer with a high efficiency is fabricated through dispersing the amine mixture of tetraethylenepentamine (TEPA) and diethanolamine (DEA) or glycerol within the as-synthesized mesoporous silica SBA-15, and the resulting sample is characterized by low angle X-ray diffraction and N2 adsorption to evaluate the distribution of the guest. The influence of hydroxyl group on the CO2 adsorption capacity of the composite is investigated by using CO2-TPD and TG–MS techniques. The hydroxyl group of the P123 ((EO)20(PO)70(EO)20, template preserved in as-synthesized SBA-15) and the guest could promote the capture of CO2 by the amine through changing the interaction mechanism. In addition, the presence of hydroxyl group promotes the formation of the intermediate between CO2 and the amine with a lower thermal stability hence the CO2 trapped by the composite is easier to be desorbed and thus the regeneration of adsorbent is facilitated. Therefore, using this mixed amine (TEPA and DEA) modified as-synthesized SBA-15 as CO2 capturer not only saves the energy for removal of template, but also cut down the cost in the preparation and regeneration of CO2 capturer, which is critical in CO2 separation and capture.