Pd-B/-gamma-Al2O3 amorphous catalysts were prepared through impregnation and KBH4 reduction for the hydrogenation of tricyclopentadiene. The effects of reduction conditions, pre-calcination and thermal annealing on the hydrogenation activity were studied. It is found that the reduction should be conducted in ice water batch with KBH4 solution added by dropping to avoid the crystallization of amorphous metals. Pre-calcination of the catalyst before reduction can increase the amount of Pd on the prepared catalyst. With pre-calcination at 200 degrees C, the highest hydrogenation turnover frequency is obtained. The amorphous catalyst is thermally stable at temperature below 150 degrees C. When annealed at higher temperature, the amorphous metals are gradually crystallized and the particle size is increased. After annealing at 600 degrees C, the catalyst is uniformly crystallized. It is noticed that the size of amorphous Pd calculated from H-2-adsorption is much smaller than the actual size observed by transmission electron microscope (TEM). This indicates that amorphous metal has stronger H-2-adsorption ability than crystal metals with comparative particle sizes. The hydrogenation activity decreases with the increase of annealing temperature. Moreover, the hydrogenation activity is solely dependent on the amount of H-2-adsorption, suggesting that the excellent performance of amorphous catalyst should be attributed to their better H-2 -adsorption ability. (C) 2007 Published by Elsevier B.V.