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

•A series of amine-dendritic CO2 adsorbents were synthesized.•CO2 adsorption capacity was measured under flue gas in fixed bed flow system.•Primary amines were the active groups within all adsorbents.•Porous polyamines could weaken diffusion resistance of CO2 adsorption.

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.

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