Preparation of Amphiphilic HZSM-5 Zeolite by Chemical Vapor Deposition of Trimethylchlorosilane

Amphiphilic HZSM-5 zeolite particles were prepared by the chemical vapor deposition (CVD) of trimethylchlorosilane ((CH3)3SiCl) followed by heating and evacuation. During CVD, (CH3)3SiCl reacted with terminal silanols on the external surface of HZSM-5 to generate hydrophobic groups. The resulting zeolite particles were hydrophobic. During heating of the zeolite particles to 423–523 K and evacuation, the (CH3)3Si groups decomposed by Si–C bond breaking, and one to two of the CH3 groups were removed off, which resulted in amphiphilic zeolite particles. This modification has little effect on the pore size and internal surface. In the phase-boundary catalytic hydrolysis of isoamyl acetate, these amphiphilic zeolite particles were located at the water-organic boundary and exhibited better catalytic activity than the parent zeolite.