Preparation and characterization of magnetic CsH2PW12O40/Fe–SiO2 nanocatalysts for biodiesel production

Abstract The magnetic CsH 2 PW 12 O 40 /Fe–SiO 2 nanocatalysts were prepared via combination of sol–gel and impregnation methods. The effects of different H 3 PW 12 O 40 /(Fe–SiO 2 ) weight percentage, loading of Cs as a promotor and calcination conditions on the catalytic performance has been studied. It was found that the catalyst with H 3 PW 12 O 40 /Fe–SiO 2  = 4 wt.% and Cs = 2 wt.% is an optimal catalyst for biodiesel production. The activity of optimal catalyst was studied in different operational conditions. The best operational conditions were CH 3 OH/oil = 12/1 at 60 °C with mechanical stirring rate of 500 rpm and the biodiesel yield reaches to 81% in 4 h. Characterization of catalysts was carried out by using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), N 2 adsorption–desorption measurements methods, Thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC).