Microporous Brookite-Phase Titania Made by Replication of a Metal- Organic Framework

摘要

Metal-organic frameworks (MOFs) provide access to structures with nanoscale pores, the size and connectivity of which can be controlled by combining the appropriate metals and linkers. To date, there have been no reports of using MOFs as templates to make porous, crystalline metal oxides. Microporous titania replicas were made from the MOF template HKUST-1 by dehydration, infiltration with titanium isopropoxide, and subsequent hydrothermal treatment at 200 ℃. Etching of the MOF with 1 M aqueous HC1 followed by 5% H_2O_2 yielded a titania replica that retained the morphology of the parent HKUST-1 crystals and contained partially ordered micro-pores as well as disordered mesopores. Interestingly, the synthesis of porous titania from the HKUST-1 template stabilized the formation of brookite, a rare titania polymorph.