Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (9): 1727-1735.doi: 10.3866/PKU.WHXB201407081

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Synthesis of Micro-Sized MEL-Type Zeolite Aggregates

CHEN Hong-Li, ZHU Shu-Yan, HE Jian-Qin, WANG Yi-Meng   

  1. Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, Shanghai 200062, P. R. China
  • Received:2014-04-22 Revised:2014-07-07 Published:2014-08-29
  • Contact: WANG Yi-Meng E-mail:ymwang@chem.ecnu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20890122) and National Key Technology R&D Program, China (2012BAE05B02).

Abstract:

Hierarchical micro-sized zeolite aggregates with the MEL structure were prepared hydrothermally froma tetrabutylammoniumhydroxide (TBAOH)-tetraethyl orthosilicate (TEOS)-H2O system. The obtained microsized silicalite-2 microspheres had sizes larger than 10 μm, high BET surface area (460 m2·g-1), and large pore volume (0.74 cm3·g-1). The formation of micro-sized spheres alleviates preparation and application difficulties. The presence of inter-crystalline mesopores originating from the spontaneous assembly of nano-sized primary particles during hydrothermal synthesis gives the advantages of nanoparticles, reducing diffusion limitations. The introduction of titanium does not strongly affect the morphology and textural properties of the MEL-type zeolite, which are quite similar to those of silicalite-2 aggregates. The micro-sized titanium silicalite-2 (TS-2) microspheres showed comparable catalytic activity in phenol hydroxylation to that of titanium silicalite-1 (TS-1) of size 100-200 nm, and were easily recovered by traditional filtration, simplifying the separation and recovery compared with nano-sized TS-1.

Key words: MEL structure, Nano-sized particle, Aggregate, Hierarchical porosity, Hydroxylation of phenol

MSC2000: 

  • O643