Indium incorporated silica samples with different indium contents were synthesized using a template free sol-gel method. The silica used was extracted from rice husk (RH) and the resulting catalyst was labeled as RH-xIn (x = 5%, 10%, 15%, and 20%). From the N2 adsorption analysis the presence of type IV isotherm in RH-blank and RH-xIn indicated the mesoporous nature of the catalysts. In the XRD pattern, a broad band at ca. 2θ = 25° was observed for all the catalysts which showed them to be amorphous. TEM micrographs revealed that the material is composed of nanoparticles. Friedel-Craft benzoylation of toluene was carried out using the RH-xIn catalyst. The optimum conditions for the benzoylation of toluene were determined and at 373 K, 100% conversion and 89% selectivity for the para-product (i.e. 4-methylbenzophenone) were obtained.

The RH-xIn catalyst, synthesized from rice husk, effectively performs Friedel-Craft benzoylation of toluene with 100% conversion and 89% selectivity for the para-product, 4-methylbenzophenone.

Heterogenization of Indium for the Friedel-Craft Benzoylation of Toluene

Key Takeaway: The RH-xIn catalyst, synthesized from rice husk, effectively performs Friedel-Craft benzoylation of toluene with 100% conversion and 89% selectivity for the para-product, 4-methylbenzophenone.