Mathematisch-Naturwissenschaftliche Fakultät

Institut für Chemie

Fachgebiet: Heterogeneous Catalysis

Betreuer: Prof. Dr. Angelika Brückner

M. Sc. Suresh Gatla
(e-mail: )

Impact of precursor materials and synthesis procedures on structure and performance of TiO2 supported Pd-catalysts in the gas phase acetoxylation of toluene

The current industrial production of benzyl acetate (BA), a valuable chemical, is based on the environmentally problematic chlorine route. Gas phase acetoxylation of toluene to BA, an eco-friendly reaction, over Pd-based catalysts using molecular oxygen can be an alternative for the production BA. To reach the industrial relevance, the catalysts should show short conditioning time and long-term stability while maintaining high activity and selectivity. To achieve this goal, different precursor materials, thermal pretreatments, co-components and support structures were varied in the catalysts synthesis. Co-components (Cu, Sb, Mn, Co, Au) altered the valance state of Pd and hereby the activity and selectivity of the catalyst. It could be shown that the coexistence of Pd and PdO on the surface is beneficial for the better performance of the catalyst. The best catalyst was achieved after a thermal pretreatment at 600 °C in helium from PdCl2 and Sb2O3. Intermixing between Pd and Sb with an atomic ratio of Pd/Sb = 5 was important for the long term stability. Surprisingly, catalyst with very high selectivity between 95 to 99 % and good long term-stability (> 30 h) was obtained with the less used rutile as support for 10 wt.-% Pd, 16 wt.-% Sb.