comparison of impregnation to deposition-precipitation methods on the performance of heterogeneous catalysts

Some key properties of catalysts prepared by two conventional preparation methods namely deposition-precipitation and impregnation methods were investigated in this paper. in addition to the mechanism of methods, some of these surveyed characters include ph, the repetitive number of washing and filtration, time and temperature of aging, drying, calcination and reduction steps. an optimization is required to each catalyst preparation step. to this purpose, suitable software such as design expert or minitab was suggested to minimize the number of experiments as well as optimize their conditions. as the results showed, the deposition- precipitation method can produce more crystallite catalysts with uniform structures. the pore size of these catalysts usually is smaller than those prepared by impregnation method. on the other hand, impregnation method would be suggested to prepare suitably catalysts owning less active metals.