Highly Efficient CeO2-MoO3/SiO2 catalyst for solvent-free oxidative coupling of benzylamines into N-Benzylbenzaldimines with O2 as the oxidant

摘要: The development of noble-metal-free catalysts is currently a topic paramount research investigation in the chemical industry. In this work, promising CeO2–MoO3/SiO2 catalyst was synthesized for oxidation wide variety benzylamines with O2 as oxidant under solvent-free conditions. For comparison, efficiency CeO2 and CeO2–MoO3 were also studied benzylamine identical physicochemical properties thoroughly analysed using X-ray diffraction, Raman spectroscopy, Barrett–Joyner–Halenda pore size distribution, Brunauer–Emmet–Teller (BET) surface area, Fourier-transform infrared ammonia-temperature programmed desorption (NH3-TPD), photoelectron spectroscopy techniques. Characterization studies revealed that shows favourable structural, textural acidic properties, which are due to strong interaction between Ce–Mo mixed oxide SiO2. particular, sample exhibits smaller crystallite highest BET area compared bare CeO2. analysis greater number oxygen vacancy defects. NH3-TPD indicated has large amount sites. Owing beneficial exhibited an outstanding catalytic performance aerobic various benzylamines. achieved conversions ~16, 65 98 %, respectively, CeO2, samples. Despite nature used reaction conditions employed, almost ~100 % selectivity dibenzylimine product found present study. Remarkably, can be repeatedly up 5 cycles without any considerable variation conversion imine selectivity. showed benzylamine, attributed abundant sites, vacancies, superior area.