An efficient heterogeneous catalyst based on highly dispersed Na7H2LaW10O36•32H2O nanoparticles on mesoporous silica for deep desulfurization

A lanthanide-containing polyoxometalate of Na7H2LaW10O36 center dot 32H(2)O (LaW10) have been chemically anchored to the amino-modified mesoporous silica through an organic linker. The catalysts have been characterized by ICP-ES, FT-IR, N-2 sorption measurements, UV-vis, MAS-NMR, and HR-TEM. It is found that the LaW10, nanoparticles are highly dispersed on mesoporous silica, and the resulting catalysts show highly efficient deep desulfurization in only 35 min with almost 100% conversion of dibenzothiophene by using (SiO2/NH3+/LaW10)/[bmim]BF4 (bmim=1-butyl-3-methylimidazolium) in the presence of H2O2 as oxidant. Furthermore, deep desulfurization proceeds smoothly in model oil with S content as low as 100 ppm. A scaled-up experiment, in which the volume of model oil increases from 5 to 1000 mL with S content of 1000 ppm, indicates that almost 100% sulfur removal can be achieved in 45 min. Additionally, the catalyst could be recycled and reused at least ten times without any decrease of the catalytic efficiency. To the best of our knowledge, the (SiO2/NH3+/LaW10)/[bmim]BF4 catalyst system with H2O2 as oxidant exhibits great potential for practical application as desulfurization systems reported so far. (C) 2013 Elsevier B.V. All rights reserved.