Mesoporous silica as supports for Pd-catalyzed H2O2 direct synthesis: Effect of the textural properties of the support on the activity and selectivity

• Published in: Journal of catalysis Vol. 273; no. 2; pp. 266 - 273
• Main Authors: Ghedini, Elena, Menegazzo, Federica, Signoretto, Michela, Manzoli, Maela, Pinna, Francesco, Strukul, Giorgio
• Format: Journal Article
• Language: English
• Published: San Diego Elsevier BV 28-07-2010
• Subjects: Catalysis; Chemical synthesis
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2010.06.003

SBA-15 allows preparing palladium catalysts with enhanced productivity and selectivity in the direct synthesis of hydrogen peroxide by imparting Pd particles the proper size and distribution. Pd-based catalysts supported on commercial silica, SBA-15 and MCM-41 were tested for the direct synthesis of hydrogen peroxide under very mild conditions of temperature and pressure and outside the explosion range. Silica and SBA-15 impart good catalytic activity, selectivity, mechanical stability and reusability. Best results were obtained with SBA-15 samples that show higher productivity than plain silica. Further catalytic tests were performed at higher pressures, still outside the explosive region. Even under these reaction conditions, the SBA-15 catalysts are the most selective. Characterization data indicate a close correlation between the textural properties of the support and the catalytic activity of the examined samples. The mean Pd particle size observed on the SBA-15 is a good compromise between a high metal dispersion necessary for high catalytic activity and the presence of less energetic sites, on which O2 can chemisorb without dissociation. [PUBLICATION ABSTRACT]