Supported ionic liquid nanoparticles (SILnPs) having particle size ranging from 293 ± 2 to 610 ± 11 nm have been prepared by immobilization of ionic liquid, 1-(tri-ethoxy silyl-propyl)-3-methyl-imidazolium hydrogen sulfate (IL-HSO 4 ) on the surface of silica nanoparticles. The catalytic activity of the prepared SILnPs was investigated for the dehydration of fructose to 5-hydroxymethylfurfural (HMF) in the presence of dimethylsulfoxide (DMSO) as a solvent. The reaction temperature and amount of catalyst have been optimized for dehydration of fructose over SILnPs using experimental design leading to 99.9% fructose conversion and 63.0% HMF yield using silica SILnPs (d = 610 ± 11) nm at 130.0• C in 30 min reaction time. The SILnPs catalysts developed in this study present improved performances over other zeolites and strong acid ion exchange resin catalysts, and they have been efficiently and very easily recycled over seven times without any significant loss in fructose conversion and HMF yield.

Nanocrystalline zirconia samples having predominantly tetragonal crystalline phase were synthesized using sol-gel and conventional precipitation techniques from zirconium hydroxide obtained by the hydrolysis of both zirconium propoxide and zirconium oxychloride precursors. Thermal drying of zirconium hydroxide gel in an oven (110 °C, 12 h) results in lower crystallite size (11-13 nm) as compared to drying under vacuum (50 mbar, 70 °C), which shows higher crystallite size (20-21 nm) during both sol-gel and conventional precipitation synthesis. The progressive transformation of tetragonal to monoclinic phase of zirconia with increasing calcination temperature was observed to be related to the critical crystallite size and lattice strain. Sol-gel synthesis was found to be advantageous because of the stabilization of tetragonal phase at higher temperature, whereas complete phase transformation was observed in the samples prepared by precipitation method at 600-700 °C temperature. Sol-gel synthesis resulted in spherical-shaped particles whereas cubic-/ rectangular-shaped particles of varying sizes were predominantly formed by conventional precipitation synthesis.

Noble metal Rh supported on a large pore high acidic zeolite Hβ has been explored as a hydrodearomatization catalyst. The detail kinetic study of hydrodearomatization of toluene over a 1 wt % Rh/Hβ was done in a continuous-downflow stainless steel catalytic fixed bed reactor at varied space time, toluene feed rate, hydrogen partial pressure, hydrogen to toluene mole ratio, temperature, and in the presence of dibenzothiophene. The time on stream data and reaction order with respect to toluene were measured and was found to be of first order. Fourier transform infrared (FTIR) spectra and chemical analysis of fresh and spent catalyst suggested the presence of surface carbon species and weight percent carbon was found to be 4.43%. It was observed that toluene conversion was increased on increasing H 2 partial pressure and H 2 /feed mole ratio. The conversion is dependent on temperature and shows a well-defined maximum. The decrease of the catalyst activity in the presence of dibenzothiophene is mainly attributed to the adsorption and decomposition of dibenzothiophene (DBT) on the metal sites, which results in a loss of metal surface available for the reaction to take place and a higher coke formation reducing the fraction of acid sites available for toluene hydrodearomatization. A nonlinear semiempirical kinetic model was also developed to have the best fit with 12% error.