02100nas a2200253 4500008004100000022001400041245024000055210006900295260009500364300001200459490000800471520100600479653002201485653002701507653002301534653001801557653002901575100002601604700002201630700001801652700001901670700002801689856012901717 2013 eng d a0021-951700aEpoxidation 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 performance0 aEpoxidation of styrene by tbutyl hydroperoxide over gold nanopar a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcAPR a217-2240 v3003 a
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. (C) 2013 Elsevier Inc. All rights reserved.
10aAu/Yb2O3 catalyst10aEpoxidation of styrene10agold nanoparticles10aStyrene oxide10atert-Butyl hydroperoxide1 aChoudhary, Vasant, R.1 aDumbre, Deepa, K.1 aPatil, N., S.1 aUphade, B., S.1 aBhargava, Suresh, Kumar uhttp://library.ncl.res.in/content/epoxidation-styrene-t-butyl-hydroperoxide-over-gold-nanoparticles-supported-yb2o3-effect-0