Synthesis of magnetic core@dual shell Fe 3 O 4 @ SiO 2 @ WO 3 nanocatalysts for olefin double bond oxidative cleavage

Herein, we report a new and efficient method for preparing Fe 3 O 4 @SiO 2 @WO 3 core@dual shell nanocatalysts featuring enhanced catalytic activity for the oxidative cleavage of the oleic acid double bond and fast magnetic separation. Various characterization techniques including EDS, XPS, SEM, and advanced elemental HRTEM mapping were used to characterize this type of magnetic core@dual shell nanocatalysts. The obtained core@shell structure is composed of a central magnetite core with a strong response to external fields, an interlayer of SiO 2 , and an outer layer of WO 3 nanocrystals. This core@shell nanocatalyst exhibited higher catalytic activity than reported tungsten based heterogenous catalysts for the oxidative cleavage of the oleic acid double bond. The presence of the SiO 2 interlayer prevents any deterioration of the catalytic efficiency of the WO 3 nanocrystal shell as well as the chemical and thermal stability of the Fe 3 O 4 core. This nanocatalyst can be easily recycled by applying an external magnetic field while maintaining its catalytic activity during at least three cycles of use.