SYNTHESIS OF HYDROXY-Ni-AI PILLARED CLAYS CONTAINING MIXED-METAL COMPLEXES
Zhao, Dong-yuan; Yang, Ya-shu and Guo, Xie-xian(Dalian Institute of Chemical Physics, Academia Sinica, Dalian 110023)
A series of hydroxy-M-Al cross-linked montmorillonites (Ni-Al--CLM) were prepared by two new methods, i. e. substitution and copo-lymerization. According to the 27A1-NMR and UV spectra of the pillaring solution, it may suggest that the hydroxy-M-Al oligomer having the structure of Keggin can be prepared by these two methods. Ni-Al-CLM prepared by substitution method shows only one (001) peak with d(001) value of 1.80 nm. But for Ni-Al-CLM prepared by copolymeriza-tion, there are two (001) peaks with basal spacing of 1.80 nm and 1.55 nm. The heat treatment of the pillaring agents before cross-linking or after cross-linking reaction was first performed on Al-CLM and Ni-Al--CLM, the higher thermal stability of these clays was resulted as compared with the untreated samples.