Abstract: Aseries of solidified bodies of kaolin, mixed with USYtype molecular sievs, were prepared by using the hydrothermai hot-pressing technique, The phase transformation, surface acidity, and catalytic cracking reaction of R- pentadecane were investigated.The results show that the temperature of solidification is one of the important factors which influence the properties of the solidified bodies under the condition of hydrothermai hot-pressing and that the solidified bodies of USY-kaolin have majority of Bronsted acid sites and few Lewis acid sites.The activity and gasolin conversion of the solidified bodies at 135℃ for n-pentadecane cracking are higher than those of the untreated sample.The surface acidity and catalytic characters of solidified bodies can be adjusted by means of changing compositions of the initial mixture and the conditions of solidification.

Key words: USY type molecular sieve, Kaolin, Surface acidity, Hydrothermal hot-pressing solidification, s-pentadecane cracking