Synthesis and Characterization of Al-Cr-Pillared Montmorillonite with High Thermal Stability and Adsorption Capacity

Al-Cr-pillared montmorillonite was synthesized by using bentonite and Al-Cr pillaring solutions as starting materials. The basal spacing and specific surface areas of the materials were significantly increased relative to those of untreated clays. When the Al/Cr molar ratio(R) was 0.10, the d(001 ) value and specific surface area of pillared montmorillonite were 1.9194 nm and 165.7 m^2 g^-1 , respectively. Thermal stability of the materials was determined using calcined tests and X-ray diffraction ( XRD ) analysis. The materials formed at different R(0.05;0.10;0.15;0.25) exhibit a high thermal stability at 300℃ , especially at initial R = 0.10, the basal interlayer spacing of materials is stabilized at 1.7313 nm after calcined at 500℃ for 2 h. Adsorption behavior of the materials was studied by adsorption experiments. The results show that the Al-Cr-pillared montmorillonites exhibit much stronger adsorption capacity on Cr^6 in aqueous solution than untreated clays do.

Synthesis and characterization of Al−Cr-pillared montmorillonite with high thermal stability and adsorption capacity

Al−Cr-pillared montmorillonite was synthesized by using bentonite and Al−Cr pillaring solutions as starting materials. The basal spacing and specific surface areas of the materials were significantly increased relative to those of untreated clays. When the Al/Cr molar ratio (R) was 0.10, the d(001) value and specific surface area of pillared montmorillonite were 1.9194 nm and 165.7 m²g⁻¹, respectively. Thermal stability of the materials was determined using calcined tests and X-ray diffraction (XRD) analysis. The materials formed at different R(0.05;0.10;0.15;0.25) exhibit a high thermal stability at 300°C, especially at initial R=0.10, the basal interlayer spacing of materials is stabilized at 1.7313 nm after calcined at 500°C for 2 h. Adsorption behavior of the materials was studied by adsorption experiments. The results show that the Al−Cr-pillared montmorillonites exhibit much stronger adsorption capacity on Cr⁶⁺ in aqueous solution than untreated clays do. CAO Ming-li: Born in 1965 Supported by Specialized Research Fund for the Doctoral Program of Higher Education (No. 20020497005) and for University Key Teacher by the Ministry of Education, China