Epoxidation of styrene by t-butyl hydroperoxide over gold nanoparticles supported on Yb2O3: Effect of gold deposition method, gold loading, and calcination temperature of the catalyst on its surface properties and catalytic performance

作者：Choudhary V R^*; Dumbre D K; Patil N S; Uphade B S; Bhargava S K

来源：Journal of Catalysis, 2013, 300: 217-224.

DOI：10.1016/j.jcat.2013.01.002

• Epoxidation of styrene
• Styrene oxide
• Au/Yb2O3 catalyst
• tert-Butyl hydroperoxide
• Gold nanoparticles

Surface properties and epoxidation performance of Au/Yb2O3 catalyst are influenced by the method of gold deposition [viz. deposition-precipitation (DP), homogeneous deposition-precipitation (HDP) or impregnation], gold loading (0.9-6.6 wt%), and the catalyst calcination temperature (400-900 degrees C)]. The catalyst showed the best epoxidation performance when it was prepared by the HDP method and calcined at 500 degrees C. The Au/Yb2O3 catalyst even after calcination at 900 degrees C showed good activity and epoxide selectivity. Both Au-0 and Au3+ surface species were found in the catalyst calcined at 800 degrees C, but only Au-0 species were observed at the lower calcination temperatures (<600 degrees C). The selectivity for styrene oxide increased continuously with the reaction temperature (from 75 degrees C to 97 degrees C) and time (1-5 h), indicating that styrene oxide did not undergo secondary reactions under these conditions.