A KCl-doped CaO catalyst synthesized by a wet impregnation method under microwave irradiation was studied in the transesterification of refined soybean oil with methanol at 338 K. The catalyst was characterized using powder X-ray diffraction, N 2 adsorption-desorption, transmission electron microscopy, and FT-IR techniques. The basic strength of the catalysts was also determined by the Hammett indicator method. The KCl/CaO catalyst exhibited a chemical stability in the reaction medium as well as a good resistance to feedstocks with high acidity.
