Silica‐supported morpholine alkaline ionic liquid catalysts for preparation of biodiesel

Biodiesel was synthesized by transesterification of soybean oil and methanol over a silica-supported morpholine alkaline ionic liquid catalyst (SILC). Characterization of SILC was performed using H-1-nuclear magnetic resonance (H-1-NMR), Fourier-transform infrared spectroscopy (FT-IR), x-ray diffraction, thermogravimetric analysis (XRD), and nitrogen adsorption-desorption isotherms. Transesterification proceeded satisfactorily over SILC at ambient pressure and without simultaneous water removal. Under optimal reaction conditions, including 60 degrees C, 4 hours, reactant/catalyst molar ratio of 14/1, and 3-wt% catalyst, a high yield of biodiesel (94.5%) was obtained. SILC's reusability was more than six times, with no obvious decrease in catalytic activity observed.