Influence of the preparation method and the nature of the support on the stability of nickel catalysts

Abstract

The influence of the preparation method and the nature of the support on the stability of the metal dispersion in nickel catalysts was studied. Three different preparation methods, incipient wetness, ion exchange and precipitation-deposition using three different commercial supports, silica, alumina and silica-alumina were used. The metallic dispersion stability was evaluated by hydrogen adsorption measurements after high-temperature calcination of the samples before and after reduction. Results have shown that the behaviour of the samples depends on the balance between positive and negative effects in the metal-support interaction, i.e., the increase of the initial metal dispersion and its resistance against sintering and, the loss of nickel in the form of difficult to reduce interaction compounds. Interaction depends on the preparation method, but can be considerably modified during catalyst life. The reactivity of the support towards nickel plays an important role in these changes. The catalyst prepared by precipitation-deposition over silica showed the best metallic dispersion and stability.