Controlled synthesis of porous metal oxides with desired morphology has been motivating scientists to explore and develop new preparation methodologies. Among them, thermal decomposition of metal-organic frameworks (MOFs) has been employed for the fabrication of several metal oxides. In this work, this strategy is employed to prepare mesoporous and tetragonal zirconia (t-ZrO2) from metal-organic framework (UiO-66), acting as both morphological template and zirconium source. This process avoids the use and removal of extra template as well as the addition of stabilizers for t-ZrO2. After thermal decomposition at 500 °C, t-ZrO2 inherited octahedral morphology from the pristine precursor, and possessed small nanoparticles with an average size of 3.1 nm. The derived t-ZrO2 had a large surface area of 174 m 2 /g and the pore diameter of 5-8 nm. The formation mechanism of t-ZrO2 was also discussed. This simple and potentially universal strategy can be used to fabricate porous metal oxides with desired shape for many applications.

Zirconium-based MOFs of the UiO family have attracted considerable attention due to their high thermal, chemical and mechanical stability. With the aim of further exploring the applications of zirconium-based UiO-66 in acid-catalyzed reactions and elucidating the effects of the defects in UiO-66 materials on their catalytic performances, in this work, a series of zirconium-containing UiO-66 samples were synthesized by varying the synthesis temperatures and BDC/Zr (terephthalic acid/ZrCl 4 ) ratios in the synthesis system. The synthesized UiO-66 samples were characterized by X-ray diffraction (XRD), N 2 adsorption-desorption, scanning electron microscopy (SEM), thermogravimetrical analysis (TGA), temperature-programmed desorption of NH 3 (NH 3 -TPD). Their catalytic performances were investigated in transesterification of tributyrin and soybean oil with methanol. The results showed that UiO-66 samples with different amounts of defects could be successfully prepared by varying the synthesis temperatures and/or the BDC/Zr ratios used in the synthesis system. The catalytic activities of the UiO-66 materials greatly depended on their linker defects and enhanced with the increase of the defect amount. The UiO-66 was an efficient catalyst for transesterification of tributyrin and soybean oil with methanol under mild reaction conditions and its catalytic activity was comparable to other solid acid catalysts reported in the literatures. The UiO-66 catalyst was relatively stable and could be reused.

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A series of mesoporous ZSM-5-x (x = Si/Al molar ratio) supports, possessing various Si/Al ratios, were prepared without using the secondary templates, and the influences of acidity of ZSM-5-x on catalytic performance of Pt/HZSM-5-x samples prepared by the conventional wetness impregnation in naphthalene hydrogenation were investigated. The results show that decreasing Si/Al ratios of mesoporous ZSM-5 supports promotes the dispersion of the supported Pt species, and the catalytic efficiencies of Pt/HZSM-5-x samples for naphthalene hydrogenation depend on the integrated effects of the Pt dispersion, the acidity, and the mesoporous structure of ZSM-5 supports. This work provides the detailed influences of acidity of mesoporous ZSM-5 on catalytic performance of supported Pt catalysts in naphthalene hydrogenation.