the performance of msu-s and its forms modified with phosphotungstic acid (hpw) and nickel (ni) for the desulfurization and denitrogenation of model diesel fuel were studied. according to the results of the characteristic tests (n2 adsorption-desorption, xrd, sem, and nh3-tpd), heteropoly acid incorporation causes higher acidity along with a negligible loss of structural aspects, while ni impre...