The New Amorphous Alloy Preparation And Catalytic Hydrogenation Of Nitro Compounds,

Aromatic amine is an important intermediate in the fields of agricultural pesticide, medicine and dye etc. One of modern syntheses of aromatic amine is the hydrogenation of corresponding nitro-compounds. The common catalyst used in hydrogenation of aromatic amine is supported precious metal catalysts and Raney nickel, but some drawbacks still exist in these catalysts such as higher price of precious metal catalyst and environmental pollution of Raney Ni. Amorphous alloy catalysts represent a new class of materials with short-range ordering while long-range disordering structure, which may provide pathways to design excellent catalysts with high catalytic activity, better selectivity and stronger resistance to the sulfur and amine poison. Besides, less or even no environmental pollution occurred during the catalyst preparation and its application in catalysis. Much attention has been paid for these amorphous alloy catalysts, owing to its potential in the atomic reactions and green chemistry.In the present thesis, liquid phase hydrogenation of aromatic nitro-compound to aromatic amine was employed to test the catalytic performance of prepared catalysts. And nitrobenzene and p-chloronitrobenzen were chosen as the reagent. To improve the catalytic performance further, some work was made as follows: (1) microwave irradiation was used to dry the precursors of catalysts according to its special heating way; (2) different supports such as mesoporous material were applied in the liquid hydrogenation of p-chloronitrobenzen; (3) Ni-P-B amorphous catalyst was prepared to inhibit dehalogenation. The relationship between the catalytic performances and the structural and electronic characteristics was systematically studied by combining a series of characterizations and the kinetic studies. The follows were in details:1. Catalyst preparation1) Supported Ni-B amorphous catalyst was prepared by impregnating SiO₂ support with a solution containing Ni²⁺, then dried by microwave irradiation or oven, and followed by calcining and KBH₄ reducing.