Preparation and characterization of spherical nickel-doped carbonaceous resin as hydrogenation catalysts I. Carbonization procedures

摘要

A series of spherical nickel doped carbonized resin catalysts (Ni-Ca/C) was successfully prepared from bead-shaped polymer-D152 Amberlyte exchanged with Ca2+ and Ni-2+,Ni- carbonized and activated at 500-700degreesC. The effect of different preparation variables inclusive of carbonization method, carbonization temperature and steam activation on the properties of resultant was investigated. Preoxidation-multistage carbonization is most appropriate to make Ni-Ca/C have a high specific surface area, high dispersion of nickel on surface and good mechanical strength. The preoxidation promotes the crosslinking reactions during carbonization. The formation of network structure effectively restricts depolymerization reactions, loss of carbon and aggregate of nickel during carbonization. The optimal carbonization temperature was found to be in the range of 500-700degreesC and the optimal steam activation temperature in the range of 500-600degreesC. The interactions between nickel and its carbon support depend on the carbonization process and final temperature to a large extent. The proper choice of the preparation conditions allowed us to produce NiCa/C having a high degree of Ni dispersion (Ni crystallite size less than 16 Angstrom) and a very high catalytic activity in hydrogenation of propenol under atmospheric pressure of H-2 at 30degreesC. (C) 2004 Elsevier Ltd. All rights reserved.