Synthesis, characterization and CO2 capture of mesoporous SBA-15 adsorbents functionalized with melamine-based and acrylate-based amine dendrimers

Abstract

A series of novel CO2 adsorbents (SBA-15/G1–G4, SBA-15/D1–D3, SBA-15/T1–T3 and SBA-15/PAMAM1–PAMAM3) were synthesized by functionalizing SBA-15 through stepwise growth of melamine-based and acrylate-based amine dendrimers. In order to ensure that amine dendrimers had successfully grafted onto the mesopores of SBA-15, the physical properties of all the adsorbents were systematically characterized by IR spectra, thermogravimetric analysis (TGA), nitrogen adsorption/desorption, X-ray diffraction (XRD) and element analysis. Then CO2 adsorption performance was determined in fixed bed flow system under simulated flue gas (12% CO2 and 88% N2) at 30°C, 50°C and 75°C, respectively. The experimental adsorption data were analyzed and compared with theoretical and previous results. Two important findings of amine dendrimer functionalized adsorbents were revealed: primary amines were the active groups within all adsorbents and branched dendrimers could weaken diffusion resistance of CO2 adsorption. This strategy of SBA-15 grafted with amine dendrimers can provide a perspective to design further novel adsorbents for CO2 capture.