2024 : 12 : 5
Vahid Mahdavi

Vahid Mahdavi

Academic rank: Associate Professor
ORCID: https://orcid.org/0000-0001-5823-5628
Education: PhD.
ScopusId: 7004027950
HIndex:
Faculty: Science
Address: Arak University
Phone:

Research

Title
Novel synthesis of vanadium phosphorus/ cerium promoted manganese oxide (VPO/Ce-OMS-2) nanocomposite as an efficient and selective catalyst for the aerobic oxidative coupling of benzyl alcohol and aniline to imine in the liquid phase
Type
JournalPaper
Keywords
Vanadium phosphorus oxide ; Cerium metal-doped MnO2 ; VPO/Ce-OMS-2 composite ;Oxidative coupling ; Imines
Year
2024
Journal Journal of Organometallic Chemistry
DOI
Researchers Elham Shahbazi ، Vahid Mahdavi

Abstract

In this investigation, the VPO/Ce-OMS-2 composite was synthesized via the mechanochemical method and it was employed for the synthesis of imine in the liquid phase through a two-step process of oxidation of benzyl alcohol and subsequent condensation with aniline using air as an oxidant. The composite was synthesized with different mass ratios of (1:1), (1.5:1), (2:1) and (2.5:1). The effect of the VPO/Ce-OMS-2 mass ratio on catalyst activity has been investigated. As the mass ratio increases from (1:1) to (2:1), the benzyl alcohol conversion gradually increases, reaching 93% at a (2:1) mass ratio. Among the synthesized samples, the VPO/Ce-OMS-2(2:1) composite exhibited the highest selectivity towards imine formation and conversion of benzyl alcohol. Various techniques, such as XRD, FT-IR, BET, FESEM, EDX, DRS, NH3-TPD, and HRTEM, were utilized to characterize the catalysts. Results indicated that the composite synthesized with a (2:1) mass ratio has a favorable surface area, a mixture of micro-meso structures, and a high number of acidic sites, as confirmed by BET-BJH and NH3-TPD techniques. The DRS analysis demonstrated that the interaction between the two catalysts, VPO and Ce-OMS-2, enhances the selectivity for the desired product. The results clearly show the synergism effect in the combination of components VPO and Ce-OMS-2 and improving the activity and selectivity of the synthesized nanocomposite. The effects of reaction temperature, reaction time, solvents, VPO/Ce-OMS-2 mass ratio, catalyst amount, and reusability were studied. Recycling results for the VPO/Ce-OMS-2(2:1) composite show that the benzyl alcohol conversion decreases slightly after five cycles of use, and its stability is almost maintained. Optimizing the reaction conditions (0.2 g catalyst, VPO/Ce-OMS-2 mass ratio (2:1), solvent toluene, reaction temperature 90◦C, and t = 8 h) resulted in a 93% conversion of benzyl alcohol with complete selectivity for the imine.