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To better apply solid acid catalysts for hydraulic cavitation technology, a ZrO2-ZSM-5 solid acid catalyst was prepared using impregnation and ion-exchange methods. The effects of the catalyst, hydrogen peroxide, and formic acid dosages, reaction temperature, and venturi tube type on the epoxidation of soybean oil were investigated. The appropriate reaction conditions were determined through a series of experiments: n(C = C):n(HCOOH) = 1:3.0, n(C = C):n(H2O2) = 1:2.2, reaction temperature 70 °C, catalyst dosage 1 wt%, and the reaction time 3 h. The epoxy value of the optimized product reached 6.19%. After the reaction, the catalyst was recovered, and catalyst-related mechanisms were hypothesized in conjunction with related analyses. A catalytic mechanism is proposed, and an explanation is provided on how the catalyst accelerates the reaction process. It was concluded that the catalyst can be effectively applied to the epoxidation reaction under the action of hydraulic cavitation, and the reaction rate can be effectively improved. [ABSTRACT FROM AUTHOR]

Solid acid catalyst HPW/TiO2–SnO2–ZrO2 was successfully synthesized by the coprecipitation-impregnation method. The structural and morphological properties of the catalyst were characterized by XRD, FT-IR, Py-FTIR, NH3-TPD, SEM, TEM, TG, and N2-adsorption–desorption analysis. HPW/TiO2–SnO2–ZrO2 was applied in soybean oil (SBO) epoxidation, and the effects of different parameters, such as catalyst dosage, formic acid dosage, hydrogen peroxide dosage, and reaction temperature, on the relative conversion to oxirane in SBO, as well as the catalyst recyclability were investigated. The catalyst was efficient and recyclable for the epoxidation of SBO. Furthermore, the epoxidation time was effectively reduced, while the relative conversion to oxirane was increased (85.08% at 2 h). Moreover, the catalyst was easily recycled, and the epoxidation activity remained high after five cycles. [ABSTRACT FROM AUTHOR]

A new hydraulic cavitation‐assisted epoxidation scheme was developed by using a cost‐effective, environment‐friendly, and recyclable solid‐acid catalyst. SnO2‐Al2O3‐NiO/SO42− solid‐acid catalysts were prepared using co‐precipitation and impregnation methods, which were characterised by several techniques and analysed using the Hammett acidity function. The prepared catalysts were found to have a large specific surface area (53.95 m2/g) and abundant acid sites (94 μmol/g). Exhibits higher stability and more effective catalytic activity compared with H2SO4. Under the optimal reaction conditions, the relative conversion to oxirane of 86.97% was obtained in only 1.5 h of reaction time. Moreover, the catalyst could be easily separated and showed satisfactory catalytic activity after five reuse cycles. The current work has clearly demonstrated that the application of hydraulic cavitation technology to the solid‐acid‐catalysed epoxidation reaction of soybean oil can shorten the reaction time, increase the relative conversion to oxirane, and be a viable method with promising applications. [ABSTRACT FROM AUTHOR]

This study aims to develop highly efficient, recyclable solid catalysts for the epoxidation of vegetable oils. An Al2O3–ZrO2–TiO2 solid acid catalyst was prepared by a co‐precipitation/impregnation method and characterised through scanning electron microscopy, energy‐dispersive spectroscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, Fourier‐transform infrared and nitrogen adsorption–desorption analyses. The solid acid catalyst with a high surface area and typical slit pore adsorption was successfully synthesised. Al2O3–ZrO2–TiO2 also exhibits high stability and improved catalytic efficiency in the epoxidation of soybean oil. An oil conversion rate of 86.6%, which is higher than that of conventional catalysts, was obtained with a catalyst loading of 0.8 wt% and was maintained at 76.6% even after recycling the catalyst three times. The performance of the solid catalyst was slightly superior to that of H2SO4. Therefore, this novel catalyst may potentially be applicable in catalysing soybean oil epoxidation. [ABSTRACT FROM AUTHOR]