Preparation and characterization of mixed hydroxy-Fe-Al pillared montmorillonite with large basal spacing

摘要

Mixed hydroxy-Al-Fe pillared montmorillonites with large basal spacing were successfully prepared through cation-exchanging of Na~+ - montmorillonite with mixed hydroxy-Al and hydroxy- Fe pillaring solutions made from hydrolysis of corresponding metal salts, followed by calcination to convert hydroxy-A and hydroxy-Fe into intercalated polycations. According to XRD analysis, the basal spacing d(001) of pillared products dramatically enlarged from 12.7 A in the Na- montmorillonite to 81 A in the hydroxy-Fe -montmorillonite and 77.5 A in mixed hydroxy-Al-Fe-montmorillonite. The N_2 BET surface areas of the pillared montmorillonites also greatly increased to more than 200 m~2/g as compared to about 27 m~2/g for the Na-montmorillonite. IR analysis of hydroxy-Fe, and mixed hydroxy-Al-Fe pillared montmorillonites revealed a new absorption vibration at 1384 cm~(-1) wavelength. XRF elemental analysis data also showed a high content of Fe_2O_3 in the hydroxy- Fe pillared montmorillonite.