Abstract: In response to the problems of traditional titanium silicate (TS-1) molecular sieve, such as poor selectivity, low activity and poor synthesis reproducibility, SINOPEC Corporation began to organize technical research starting with the “titanium state” and the“intracrystalline pore structure” in the 1990s, a series of hollow titanium silicate molecular sieves with independent intellectual property rights were developed, which supported the first industrialization of cyclohexanone ammoximation and propylene epoxidation technology in China. Furthermore, due to the intracrystalline reaction of propylene epoxidation and the fact that surface titanium is easy to decompose H2O2, the framework titanium is mainly distributed in the crystal of molecular sieve to reduce the ineffective decomposition of H2O2. It is found that the type and number of defects have an important effect on the size and distribution of the voids, that is, the regular bulk and irregular banded voids are produced by the skeleton point defects and the grain boundary defects, respectively. Because the template cationic TPA⁺ can not enter the crystal of molecular sieve, it is inferred that the defect-dissolved and dissolved silicon-titanium species recrystallization along the external surface of molecular sieve is the basic reason of the hollow and morphology change. The research progress of HTS in structural design, catalytic performance enhancement, and catalytic oxidation applications in recent yearsis aree reviewed, with a focus on summarizing the industrial applications of HTS.

Key words: titanium silicate zeolite, hollow cavities, catalytic oxidation, cyclohexanone ammoximation, propylenen epoxidation