Design and fabrication of zeolite-based microreactors and membrane microseparators

This paper demonstrates that zeolites (i.e., Sil-1, ZSM-5 and TS-1) can be employed as catalysts, membrane or structural materials in miniature chemical devices. Traditional semiconductor fabrication technology was employed in micromachining the device architecture. The fabricated miniature zeolite-based structures find applications as catalytic microreactors and membrane microseparators. Four strategies for the manufacture of zeolite catalytic microreactors were discussed: zeolite powder coating, uniform zeolite film growth, localized zeolite growth, and etching of zeolite-silicon composite film. These zeolites were deposited either as film or discrete islands with controlled particle size, crystal morphology, layer thickness (3-16 mum) and film orientation (e.g., highly oriented (101) and (200) films). Crystal intergrowth was also manipulated through the use of growth inhibitors. Silicalite-l was also prepared as free-standing membrane for zeolite membrane microseparators. (C) 2001 Elsevier Science B.V. All rights reserved.