Effects of support on the nickel-based catalysts for hydrogenation of 2, 4-dinitrotoluene

A series Ni-based catalysts of Ni/MgO, Ni/HZSM-5, Ni/diatomite, Ni/SiO2 and Ni/HY were prepared by impregnation-precipitation method and characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption (BET) and temperature-programmed reduction (TPR), and used to catalyze the process of liquid-phase hydrogenation of 2, 4-dinitrotoluene to 2, 4-tolylenediamine. Under the reaction conditions of 2.2 MPa, 90°C, 2, 4-dinitrotoluene 5 g, solvent 300 mL, catalyst 0.5 g, the five Ni-based catalysts followed the order of Ni/HY, Ni/diatomite, Ni/SiO2, Ni/HZSM-5, Ni/MgO, according to the order from high to low of 2, 4-tolylenediamine selectivity in 2, 4-dinitrotoluene catalytic hydrogenation. The Ni/HY catalyst showed the highest catalytic activity with 2, 4-dinitrotoluene conversion of 99.94% and 2, 4-tolylenediamine selectivity of 99.40%. No obvious deactivation of the catalyst was observed after being reused for three times in the reaction.