Microwave heating was utilized in the preparation of amorphous Ni-B/SiO2 catalysts. After wetness impregnation with NiCl2 aqueous solution, the catalyst precursor was dried at 383 K, followed by microwave heating and KBH4 reduction. Liquid phase hydrogenation of acrylonitrile was employed as the probe reaction. While ICP, XRD, XPS and turnover frequency results did not reveal discernable structural and electronic differences between the active components of the catalysts with or without microwave heating, SEM uncovered the formation of smaller Ni-B alloy particles with microwave heating, leading to a higher concentration of active sites and greater thermal stability as verified by H-2 chemisorption and DSC. (C) 2003 Society of Chemical Industry.