Synthesis of MCM-41/MOR composite molecular sieves and its catalytic properties for isomerization of alkane

The MCM-41/MOR composite molecular sieves with multiple micro-mesoporous structure were hydrothermally synthesized by using the alkali-treated MOR seriflux as partial silica-alumina source and cetyltrimethylammonium bromide(CTAB) as the template in self-assembly process. The synthesized samples of molecular sieves were characterized by XRD, HRTEM, BET and Py-FTIR, respectively. The results showed that the samples exhibit a hierarchical micro-mesoporous structure, large specific surface area and good hydrothermal stability as well. The isomerization performance of the composite zeolite catalyst was evaluated in a fixed bed microreactor. The results showed that the appropriate B and L acid coordinated with each other to act as the active center of alkane isomerization, while Ni species were not only active site for this reaction, but also played a good role in the modification of acidity. Compared with Ni-MOR, Ni-MCM-41 and HMCM-41/MOR, the Ni-MCM-41/MOR catalyst had better catalytic performance for isomerization reaction, the conversion of n-hexane is 34.40%, and the selectivity of i-C₆⁰ is 40.38%.