Mesoporous cellular foams supported Fe2.0SiW12O40: Synthesis, characterization and application to CO2 sorption

Solid adsorbents comprising 50, 70, and 90 wt.% heteropolyacid Fe2.0SiW12O40 (Fe–HPA) and mesoporous cellular foams (MCFs) have been synthesized by wetting impregnation. The adsorbents were characterized by various physicochemical, thermal and spectral techniques and the CO2 adsorption capacity of the adsorbents were investigated. The structure of Fe–HPA on the surface of the support was confirmed by TEM, SAXS, XRD, SEM, FTIR, 29Si MAS NMR, and XPS. XPS of the Fe 2p3/2, 2p1/2, 3p and W 4f7/2, 4f5/2, 4d5/2, 4d3/2 confirmed the presence of typical Fe(2 +) and W(6 +) in the adsorbent, respectively. The adsorbents showed a very high adsorption capacity due to the chemisorption of CO2. The CO2 adsorption capacity of a 70 wt.% Fe–HPA–MCF sample was 111.8 mg/g-adsorbent at 25 °C. This result indicated that the reported iron (Fe2 +) complex could be used as an efficient adsorbent for the separation of CO2. The adsorbents displayed excellent CO2 adsorption capacity and were thermally stable and recyclable.