Preparation of Zirconia Promoted Sulfated Titania System with High Catalytic Activity

Abstract

SO 42-/TiO 2 -ZrO 2 (STZ) solid superacid catalysts were prepared using the coprecipitation-impregnation method and characterized by FT-IR, XRD, NH 3 -TPD, N 2 adsorption-desorption isotherms, and SEM. It was observed that the sulfur content and the specific surface area of STZ changes with the ZrO 2 content, and passes through a maximum at Zr/Ti = 1/4. The results indicate that the molar ratio of Zr/Ti and nonionic surfactant, PEG, were helpful for increasing the surface areas and stabilizing the sulfate species on the surfaces of the catalysts. The catalytic activity results were supported by the hydrolysis reaction rate of 2-methyl-1,3-dioxane (2MD) that was strongly dependent on the sulfur content in the zirconia promoted sulfated titania catalyst.

ZrO2–MoO3 for the Acetalization of 1,3-Propanediol from Dilute Solutions

“…Previous work indicated that the composition and phase of active oxide components are important to 2MD conversion. 3,7 A reversible hydrolysis reaction can also reach a state of chemical equilibrium, a steady stage in which no further changes in concentrations of reactants and products occurs, and the catalyst is the substance that affects the rate of the reaction. The hydrolysis time required to reach equilibrium was analyzed in the process.…”

“…After reaction at 40–80 °C and atmospheric pressure for 2 h, the catalyst was filtered. The reaction products were collected, and the organic phase was filtered to obtain 2-methyl-1,3-dioxane (2MD), as mentioned before. , …”

“…The reaction products were collected, and the organic phase was filtered to obtain 2methyl-1,3-dioxane (2MD), as mentioned before. 3,13 2.4.2. Hydrolysis of 2MD.…”

“…With these benefits and advantages, great efforts have been directed toward the fabrication and application of solid acid catalysts. Many types of solid acid catalysts, such as SO 4 2– /TiO 2 , SO 4 2– /M x O y , and SO 4 2– /ZrO 2 -MCM-41, have been widely used in heterogeneous catalysis, esterification, selective oxidation, asymmetric catalysis, condensation, hydration, dehydration, hydrolysis, and so on. − However, the loss of SO x in aqueous-phase reactions results in unfavorable catalyst inactivation and environmental pollution. In contrast, composite oxide solid acids with no sulfur acid have many attractive properties, such as high activity, high selectivity, good stability without leaching of active components, and absence of pollution .…”

Synthesis of High‐Purity Methylal via Extractive Catalytic Distillation

“…In recent years, due to the advantages of corrosion elimination as well as ease of recycle and regeneration [4][5][6], a series of solid acid catalysts such as cation-exchange resins, zeolite, supported heteropolyacids as well as sulfonated fluoroalkylene resin derivatives were developed to replace sulfuric acid for methylal synthesis [7][8][9][10]. In recent years, due to the advantages of corrosion elimination as well as ease of recycle and regeneration [4][5][6], a series of solid acid catalysts such as cation-exchange resins, zeolite, supported heteropolyacids as well as sulfonated fluoroalkylene resin derivatives were developed to replace sulfuric acid for methylal synthesis [7][8][9][10].…”