Oxygen-induced activation of silica supported silver in acrolein hydrogenation

• Published in: Applied catalysis. A, General General, 2008-06, Vol.341 (1), p.127-132
• Main Authors: Bron, M., Teschner, D., Wild, U., Steinhauer, B., Knop-Gericke, A., Volckmar, C., Wootsch, A., Schlögl, R., Claus, P.
• Format: Article
• Language: English
• Subjects: Acrolein; Catalysis; Chemistry; Electropositive adsorption sites; Exact sciences and technology; General and physical chemistry; Selective hydrogenation; Silver; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2008.02.033

Acrolein hydrogenation has been studied over Ag/SiO 2 catalysts in a pressure range from 266 mbar to 10 bar. Oxygen pre-treatment of the catalysts enhances activity as well as selectivity to allyl alcohol. This effect is ascribed to the formation of electropositive silver sites and/or restructuring of the catalyst. ▪ The effect of oxygen pre-treatment of Ag/SiO 2 catalysts used in the acrolein hydrogenation has been investigated from sub-atmospheric (266 mbar) to 10 bar reaction pressure. The pre-treatment has a profound influence on the overall hydrogenation activity, inasmuch the activity increased two- to three-fold. Oxygen pre-treatment also enhanced the selectivity towards the desired allyl alcohol. The beneficial effect of oxygen pre-treatment is ascribed to the formation of electronically modified Ag and/or morphology changes of the nanoparticles as no modification in particle size or dispersion was found.