A General and Simple Method of Preparing Molybdenum‐ Incorporated Silica Nanoparticles as Potential Catalysts for Epoxidation of Alkenes. Issue 31 (20th August 2018) - Shen, Yirui
Abstract: Molybdenum incorporated silica nanoparticles were synthesized by a general and simple method and developed as efficient catalysts for epoxidation of alkenes with high performance. The nanoparticles were prepared in mild conditions with cetyltrimethyl ammonium bromide as template, tetraethyl orthosilicate as silica source and triethanolamine as mineralizing agent. Molybdenum precursor was added during the sol‐gel process and transferred to active sites MoO3 after calcination. Remarkably, the shape of silica nanoparticles gradually changed from raspberry to rose with the rising dosage of molybdenum precursor. The materials were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption/desorption, inductively coupled plasma‐atom emission spectroscopy (ICP‐AES) and X‐ray photoelectron spectra (XPS). To determine the reactivity of catalysts, epoxidation of cyclooctene was carried out as a model reaction. After 12 h reaction with H2 O2 (50 wt%), above 92% conversion and 95% selectivity were reached. Furthermore, the catalyst still had high conversion (74%) and selectivity (97%) for 4 h epoxidation of cyclooctene even after being recycled for 6 runs. Abstract : A novel one‐pot method was developed to prepare molybdenum incorporated silica nanoparticles as potential catalysts for epoxidation of alkenes with high conversion and selectivity. Molybdenum precursor was added during the sol‐gel process of silica source. After 12 h reaction with H2 O2 (50 wt%), above 92% conversion and 95% selectivity were reached. The catalyst still had high conversion (74%) and selectivity (97%) for 4 h epoxidation of cyclooctene after recycling for 6 runs.