Synthesis and characterization of nano-sized nickel catalyst supported on SiO2–Al2O3

Abstract

support on thecatalytic activity of nickel catalyst. The reaction used in this studywas the hydrogenation of p-nitrophenol into p-aminophenol.p-Aminophenolisconsideredtobeveryimportantintermediateinthemanufactureofmanyanalgesicandantipyreticdrugs,suchasparacetamol,acetanilide,phentacin,...etc.[9–15].Itisalsousedasadeveloper in photography (under trade names of activol or azol), inaddition of its use in chemical dye industries [16].There are several methods used in the preparation of p-aminophenolfromp-nitrophenolsuchas:(1)metal/acidreduction[17], (2) catalytic hydrogenation [18], (3) electrolytic reduction[19], (4) homogeneous catalytic transfer hydrogenation [20], and(5) heterogeneous catalytic transfer hydrogenation, etc.Among all previously mentioned methods, direct catalytichydrogenation of p-nitrophenol to p-aminophenol becomes themost important one. This is because it could be an efficient routefor synthesis [15]. Raney nickel [21], nano-sized nickel [22] andseveral noble metal catalysts, such as Pd/C [15], have been used ascatalysts for this reaction. Due to their lowest cost and highercatalytic activity, supported nickel catalysts, are widely used insuch reactions [15–21].Although nickel catalyst is used in hydrogenation reactions[23–29], only few recent researches have been carried out onhydrogenation of p-nitrophenol over nano-sized supported nickelmetal catalyst [10,30,31].The present investigation reports the results of an intensivestudy on preparation and characterization of nano-sized metallicnickel supported on SiO