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Flower-like mesoporous sulfated zirconia nanosheets (SZNs) were developed by thermal decomposition of in situ sulfated Zr-MOFs for the first time. The sulfated Zr-MOFs act as both a morphological template and zirconium and sulfate sources. The amounts of SO42− in the synthesis system of UiO-66 greatly affected the morphology of sulfated Zr-MOFs via a coordination modulation method. The flower-like sulfated Zr-MOF nanosheets were obtained as the S/Zr ratio increased to 0.5. The calcination temperature has a great influence on the structural properties and catalytic performances of sulfated zirconia nanosheets other than morphology. Sulfated zirconia nanosheets (SZN-500) obtained by calcination at 500 °C had a large surface area (186.1 m2 g−1) and strong bonding between sulfate and zirconia atoms and exhibited a good catalytic activity and reusability for the transesterification of tributyrin with methanol. This viable synthetic strategy can offer an alternative way to prepare functionalized metallic oxides with a specific morphology. [ABSTRACT FROM AUTHOR]

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 a metal–organic framework (UiO-66), acting as both a morphological template and a zirconium source. This process avoids the use and removal of an extra template as well as the addition of stabilizers for t-ZrO2. After thermal decomposition at 500 °C, t-ZrO2 inherited an 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 m2 g−1 and a 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. [ABSTRACT FROM AUTHOR]

Abstract: By using zirconia as promoter, a highly ordered mesoporous alumina with extremely high thermal and hydrothermal stability has been synthesized successfully via an evaporation-induced self-assembly (EISA) pathway associated with thermal treatment. In comparison to pure mesoporous alumina, the resultant mesoporous zirconia–alumina nanomaterials maintain the ordered hexagonal mesostructure, narrow pore-size distribution, high BET surface area and pore volume even after thermal treatment at 1000°C or boiling water treatment for 6h. Our contribution provides an important approach to synthesize ordered mesoporous Zr–Al nanomaterials with high thermal and hydrothermal stability, which can find potential application for the catalytic applications in the petroleum industry. [Copyright &y& Elsevier]

Graphical abstract Highlights • Micro-mesoporous alumina-zirconia nanocrystals are prepared by vapor-induced route. • The Al incorporation improves the textural properties of the composites. • The largest surface area of 313 m2/g is obtained. • The samples possess stable tetragonal structure of zirconia. • The samples show large pore volumes in the range of 0.18–0.39 cm3/g. Abstract Micro-mesoporous alumina-zirconia nanocrystals with controllable textural properties are prepared using triblock copolymer F127 as a template via one-pot vapor-induced pathway. The BET surface area and pore volume of the samples increase with rising aluminum content. When the Al/Zr molar ratio is 0.6, the sample exhibits highest surface area of 313 m2/g of which 118 m2/g in the form of micropores after high temperature calcination. Moreover, the incorporation of Al species enhances the structural stability of zirconia in tetragonal phase. [ABSTRACT FROM AUTHOR]

A double-chain quaternary ammonium salt of dioctyl dimethyl ammonium chloride (DDAC8) was first used as a low-cost template to prepare the mesostructured zirconia nanomaterials in an alcohol-thermal system. The material was calcinated to obtain pure tetragonal crystalline zirconia ( t -zirconia) and thus has significantly improved original structure properties, including a narrow pore size distribution of 4–7 nm and a high surface area of 195 m 2 /g. The t -zirconia hierarchical nanoparticle aggregate material is different from the smooth microsphere material obtained using the single chain quaternary ammonium salt template. The characteristic rough surface morphology results from the grid distribution form of the DDAC8 micelles in the ethanol solution and caused the formation of more defect sites, which demonstrate the potential for possible catalytic applications. A formation mechanism of the mesoporous zirconia nanomaterial in the alcohol-thermal system of the surfactants is reasonably explained. The synthesis system may provide a new approach to the preparation of mesoporous nanomaterials. [ABSTRACT FROM AUTHOR]

The super-microporous microcrystalline MgO-ZrO 2 nanomaterials (pore size 1–2 nm) was prepared successfully via a facile one-pot evaporation-induced self-assembly (EISA) method and employed in the transesterification of soybean oil and methanol. X-ray diffraction, transmission electron microscope, temperature programmed desorption of CO 2 , and N 2 adsorption porosimetry were employed to characterize the nanocomposites. Nitrogen sorption isotherms revealed that these materials had large surface areas of more than 200 m 2 /g. Moreover, the sample with a Mg/Zr molar ratio of 0.5 and calcined at 400 °C showed high biodiesel yield (around 99% at 150 °C). [ABSTRACT FROM AUTHOR]

A sulfated zirconia catalyst has been prepared by a novel one-pot vapor-controlled synthesis route using ammonium persulphate as sulfate agent. A possible formation mechanism of the catalyst is proposed. The effect of calcination temperature and S/Zr molar ratio on the structural, textural and catalytic properties of the prepared catalyst were investigated in detail using X-ray diffraction (XRD), N 2 adsorption–desorption, ammonia temperature programmed desorption (NH 3 -TPD), Fourier transform infrared spectroscopy (FTIR) and a scanning electron microscope (SEM) which was equipped with an energy dispersive spectroscope (EDS). The results indicated that the samples calcined at 500 °C possessed zirconia of pure tetragonal structure, more content of sulfur and better distribution of acid sites on the surface of zirconia compared with the samples calcined at 600 °C at fixed S/Zr molar ratio. Moreover, they showed excellent catalytic activity with 100% yields of biodiesel for the transesterification of soybean oil with methanol. [ABSTRACT FROM AUTHOR]

A super-microporous zirconia–alumina (pore size in the range of 1–2 nm) with narrow pore size distribution has been synthesized successfully by using an inexpensive nonionic surfactant fatty alcohol polyoxyethylene ether (AEO-7) as the template in ethanol solvent. As the Zr/Al molar ratio is 0.1, the material has high surface area of 413 m 2 /g and a large pore volume of 0.17 cm 3 /g after calcination at 400 °C. Even after calcination at 900 °C, the microporous structure remained, exhibiting a significant thermal stability. [ABSTRACT FROM AUTHOR]