Work

Development of Molybdenum oxide Promoted CeO 2 −SiO 2 Mixed‐oxide Catalyst for Efficient Catalytic Oxidation of Benzylamine to N‐Benzylidenebenzylamine

Year: 2024

Type: article

Abstract: This study explores a rational synthesis of a molybdenum‐promoted Ce−Si mixed oxide catalyst (MoO 3 /CeO 2 −SiO 2 ) to regulate synergies between MoO 3 and SiO 2 dopant on CeO 2 , achieving high selectivity in solvent‐free catalytic oxidative coupling of amines to imines using molecular O 2 as the oxidant. Comparative efficiency tests were conducted with bare CeO 2 , CeO 2 −SiO 2 , and MoO 3 /CeO 2 catalysts. Characterization techniques, including XRD, Raman spectroscopy, N 2 ‐adsorption‐desorption analysis, FTIR, NH 3 −TPD, TEM, and XPS, were employed to assess textural properties, acidic features, promoter and dopant dispersion in CeO 2 lattice, and oxygen defects. Mo/Ce−Si catalyst exhibited superior acidic sites and a higher concentration of Ce 3+ ions (I u /I Total ), indicating increased oxygen vacancies. This catalyst demonstrated exceptional performance in the oxidative coupling of benzylamine, providing higher conversion and selectivity to the corresponding imine. Remarkably, the Mo/Ce−Si catalyst maintained consistent performance over five recycling runs. The catalyst also proved effective for the selective oxidative coupling of various amine substrates with diverse steric and electronic properties. Experimental results confirmed a plausible reaction mechanism within the concise catalyst design.

Source: ChemistrySelect

DOI: 10.1002/slct.202304534