Preparation of Coimpregnated Cu−Zn on Zn-Modified Silica: Influence of the Basicity of the Support and of the Nature of Zinc Species on the Catalyst Properties

• Published in: Journal of physical chemistry. C Vol. 114; no. 25; pp. 11140 - 11147
• Main Authors: Catillon-Mucherie, Stéphanie, Lauron-Pernot, Hélène, Louis, Catherine
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01.07.2010
• Subjects: C: Surfaces, Interfaces, Catalysis
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp100252h

In this paper, we showed that the addition of zinc on silica support by impregnation with zinc nitrate or chloride (10 wt % Zn) followed by calcination at 450 °C modifies the properties of the oxide surface and induces different basic properties as determined by the test-reaction of conversion of methylbutynol. Basicity depends on the zinc species formed during calcination, zinc silicate of hemimorphite-type (Zn4Si2O7(OH)2·H2O) for the zinc nitrate precursor and isolated grafted zinc species ((SiO)2ZnCl(O), with (O) = OH or H2O) for the zinc chloride precursor. Basicity of the support favors the formation of hydroxy-compound during further impregnation with copper or copper−zinc nitrate. The dispersion and crystallinity of these precursors directly govern the final state of the catalyst after reduction, i.e., the copper particle size and the extent of the Cu0−ZnII interactions; the latter is attested through the test-reaction of selective hydrogenation of crotonaldehyde.