Clean Technology 2011
H. Zheng, P.G. Weidler, Y. Pu, P. Cai, Y. Wu
School of Materials Science and Technology, China University of Geosciences, CN
Fe/Al-PILCs, calcination conditions, Fe/Al molar ratio, structure, property
In this paper, solutions containing hydroxyl-FeAl oligocations with Fe/Al molar ratio of 0.5 and 1.0 were prepared by adding Na2CO3 solution to mixture of FeCl3 and AlCl3 with constant stirring until a final OH/(Al+Fe) ratio of 2.0, followed by aging for two weeks and aging at 120C for 4 h before use. Ion-exchange of Na-volclay provided by Südchemie AG with hydroxyl-FeAl oligocations yield intercalated clay. The pillared clay samples were obtained by calcinating up to different temperature with heat rate of 1C/min for 2h or calcinating directly the dried intercatalated products for 2 h at different temperature. Calcination conditions and Fe/Al molar ratio on structure and properties of Fe/Al-PILCs were discussed. The results show that larger basal spacing (d001) of Fe/Al-PILCs can be obtained when Fe/Al molar ratio is 0.5 than that is 1.0. The thermal stability of Fe/Al-PILCs are decreased with increasing calcination temperature and Fe/Al molar ratio. The structure of Fe/Al-PILCs is easier to be destroyed by calcinating directly the intercatalated products at specific temperature than calcinating up to different temperature with heat rate of 1C/min. Cation exchange capacities (CEC) of Fe/Al-PILCs decrease with increasing of calcination temperature. Both BET surface areas and porosity of Fe/Al-PILCs greatly increase after pillaring. Fe/Al-PILC with the largest BET surface areas and porosity is obtained when Fe/Al molar ratio is 0.5, calcinated up to 400C with heat rate of 1C/min for 2h. Fe/Al-PILCs obtained under experimental conditions are mesoporous materials and are found to be excellent adsorbent for metal cations and anions.