NICKEL ON SILICA SYSTEMS - SURFACE-FEATURES AND THEIR RELATIONSHIP WITH SUPPORT, PREPARATION PROCEDURE AND NICKEL CONTENT

The characteristics and structure of several silica-supported nickel s ystems, prepared by impregnation and precipitation-deposition and in a wide range of nickel contents (from 0.58 up to 69 wt% Ni), have been studied. Using mainly conventional sorption techniques the textural pr operties - BET surface area, pore volume, average pore radius, pore si ze distribution - and surface chemical distribution - nickel surface a rea, reduction degree, dispersion, crystallite particle diameter - of the samples have been determined. All these characteristics have been related to each other and globally analyzed to advance in the understa nding of the final structure of the catalysts and its relationship wit h support structure, preparation procedure and nickel content. (C) 199 7 Elsevier Science B.V.