Study on Solvent/Alkoxide Molar Ratios on Synthesis Zirconia Nanoparticles for Tungstated Zirconia Catalysts Over Esterification

Wongmaneenil, Peangpit; Jongsomjit, Bunjerd; Praserthdam, Piyasan

doi:10.1007/s10562-010-0403-3

Cited by 7 publications

(7 citation statements)

References 34 publications

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“…It reveals that strontia loading decreases the BET surface area sharply, which is in good agreement with studies conducted by other researchers. 20 It was concluded that strontia crystals assemble on surface or in pores of sulfated zirconia. Fig.…”

Section: Resultsmentioning

confidence: 99%

Preparation of Supported Nanosized Sulfated Zirconia by Strontia and Assessment of Its Activities in the Esterification of Oleic Acid

Nayebzadeh

Saghatoleslami

Maskooki³

et al. 2014

Chem.Biochem.Eng.Q.

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The aim of this study was to examine a new nanocatalyst of SrO/S-ZrO 2 in esterification reaction and the optimum value of strontia loading over the sulfated zirconia. The sulfated zirconia was supported with different molar ratios of strontia in the range of 0.0-0.30, using the solvent-free method. The samples were characterized using XRD, FT-IR, BET and TEM analysis and their activity were investigated in esterification reaction of oleic acid. The findings of this study revealed that 25 mol % SrO/S-ZrO 2 had the highest yield in the esterification reaction. It was also concluded that strontia-supported sulfated zirconia could improve the low reusability of the catalyst. Furthermore, 95 % conversion was also obtained at optimized conditions (i.e., 100 °C, 2 wt. % of catalyst, 6:1 molar ratio of methanol/oleic acid and for a period of 30 minutes).

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Section: Resultsmentioning

confidence: 99%

Preparation of Supported Nanosized Sulfated Zirconia by Strontia and Assessment of Its Activities in the Esterification of Oleic Acid

Nayebzadeh

Saghatoleslami

Maskooki³

et al. 2014

Chem.Biochem.Eng.Q.

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“…[18] Due to high acid strength and good stability in comparison with sulfated zirconia, the WO x /ZrO 2 composites also enable wide applications in diverse acid-catalytic reactions. [19][20][21][22][23][24][25][26] Notably, the catalytic activity was demonstrated to be dependent on surface acid density, which was closely associated with the density (W atoms/nm 2 ) and dispersion (electronic structure and domain size) of WO x species supported on ZrO 2 . Therefore, the surface acid density of WO x /ZrO 2 can be controlled by tuning tungsten amount, calcination temperature, and surface area of ZrO 2 supports.…”

Section: Introductionmentioning

confidence: 97%

“…Through incorporating tungsten on zirconia, the WO x /ZrO 2 composites were first reported as novel solid superacid catalysts for isomerization of butane and pentane [18] . Due to high acid strength and good stability in comparison with sulfated zirconia, the WO x /ZrO 2 composites also enable wide applications in diverse acid‐catalytic reactions [19–26] . Notably, the catalytic activity was demonstrated to be dependent on surface acid density, which was closely associated with the density (W atoms/nm 2 ) and dispersion (electronic structure and domain size) of WO x species supported on ZrO 2 .…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, the surface acid density of WO x /ZrO 2 can be controlled by tuning tungsten amount, calcination temperature, and surface area of ZrO 2 supports [8,27–31] . However, conventional incipient‐wetness impregnation and co‐precipitation methods usually result in WO x /ZrO 2 composites with low surface area, uncontrollable and non‐homogeneous distribution of polytungstate species, and low catalytic activity [26,32] . Therefore, considerable efforts have been devoted to developing feasible strategies, such as microwave‐assisted method, [25] two‐phase interface hydrolysis method, [33] and anionic exchange method, [34] in order to obtain WO x /ZrO 2 catalysts with higher specific surface area and desired exposed active sites.…”

Section: Introductionmentioning

confidence: 99%

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Controllable Multicomponent Co‐Assembly Approach to Ordered Mesoporous Zirconia Supported with Well‐Dispersed Tungsten Oxide Clusters as High‐Performance Catalysts

Yang

Yuan

et al. 2021

ChemCatChem

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Zirconia supported WOx clusters with high acid strength and good stability are important solid acid catalysts in many reactions. However, conventional synthetic methods such as incipient‐wetness impregnation and co‐precipitation usually result in the products with low catalytic activity due to low surface area, uncontrollable and non‐homogeneous distribution of tungsten species. In this study, a facile multicomponent co‐assembly approach was utilized to straightforwardly synthesize ordered mesoporous WOx/ZrO2 composites (OMWZr) with mesopore size over 17 nm, pore volume of 0.13–0.18 cm3/g and surface area of 27.3–41.7 m2/g. The materials were composed of robust crystalline ZrO2 skeleton and well‐dispersed WOx clusters (polytungstates) in framework under the optimized conditions. The tungsten species were well stablized by the crystallized skeletons of mesoporous ZrO2, which can inhibit the growth of tetragonal ZrO2 but facilitate crystallization of monoclinic ZrO2. The states of tungsten species (monotungstates, polytungstates and crystalline WO3) can be precisely adjusted by their doping amount in framework and calcination temperature as well, which can further tune the surface acidity of OMWZr composites. Owing to the existence of numerous active surface WOx clusters generated over exposed surface of mesoporous ZrO2, the OMWZr catalysts not only show great spatial homogeneity of accessible Brønsted acid sites and feasible mass diffusion during catalytic reactions, but also display outstanding acid‐catalytic performance over hydrolysis reactions of benzaldehyde dimethyl acetal. The catalyst can be reused for more than 10 cycles, without reduction of catalytic activity and selectivity to benzaldehyde.

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“…Different alcohols were indeed investigated by Anandan et al [24], but the obtained samples were all monoclinic. The aim of the present work is thus to determinate if the solvent is a valid synthesis parameter with the same importance as temperature or the nature of the metal precursor or its concentration [25].…”

Section: Introductionmentioning

confidence: 99%

Solvent effect in the nonaqueous synthesis of ZrO2 nanoparticles under alkaline conditions

et al. 2019

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This work deals with the synthesis of zirconium dioxide (ZrO2) nanoparticles (NPs) in different solvents and their structural characterization for better understanding the oxygen donor solvent/zirconium precursor/NPs structure relationships. By selecting solvents over their capacity to produce different crystalline states from alkalinized zirconium alkoxide, spherical nanoparticles with a size of about 1.3 to 3 nm and a narrow size distribution were elaborated using a nonaqueous solvothermal sol-gel route. Conventional X-ray diffraction (XRD) was used to determine the average structure and crystallite size of the nanoparticles. Well crystallized and single-phased nanoparticles with average monoclinic and tetragonal structure were obtained with benzaldehyde and benzyl alcohol respectively, and a much distorted structure was observed for the synthesis in anisole. The atomic pair distribution functions (PDF) of the samples were also analyzed to access the local structure of the nanoparticles. The PDF of the benzaldehyde-prepared sample is consistent with the monoclinic structure. However, the local structure of nanoparticles synthesized with benzyl alcohol does not fully conform to the tetragonal structure observed by XRD but exhibits monoclinic-like distortions. Lastly, the anisole-prepared nanoparticles present large structural distortions at the medium-range and monoclinic local structural features. The restructuring of this last sample was studied by posttreatments in different solvents and leads to the expression of the tetragonal polymorph. Moreover, it seems that the main structural features are obtained in the early stages of the nanoparticles' formation.

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Study on Solvent/Alkoxide Molar Ratios on Synthesis Zirconia Nanoparticles for Tungstated Zirconia Catalysts Over Esterification

Cited by 7 publications

References 34 publications

Preparation of Supported Nanosized Sulfated Zirconia by Strontia and Assessment of Its Activities in the Esterification of Oleic Acid

Preparation of Supported Nanosized Sulfated Zirconia by Strontia and Assessment of Its Activities in the Esterification of Oleic Acid

Controllable Multicomponent Co‐Assembly Approach to Ordered Mesoporous Zirconia Supported with Well‐Dispersed Tungsten Oxide Clusters as High‐Performance Catalysts

Solvent effect in the nonaqueous synthesis of ZrO2 nanoparticles under alkaline conditions

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