Hydroperoxide intermediates in propylene epoxidation on gold/titanosilicate catalysts

PETR 22

S. Ted Oyama, oyama@vt.edu1, Juan J. Bravo-Suárez, juan-bravo@aist.go.jp2, Jiqing Lu2, Kyoko K. Bando2, and Tadahiro Fujitani, t-fujitani@aist.go.jp2. (1) Department of Chemical Engineering, Virginia Tech, 140 Randolph Hall, Blacksburg, VA 24061, (2) Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba West, 16-1 Onogawa, Tsukuba, 305-8569, Japan
Catalysts consisting of nanoparticles of gold supported on a mesoporous Ti silicate (TUD) with pores of 13 nm were synthesized and used for the epoxidation of propylene with mixtures of H2 and O2. In situ studies with XANES, UV-vis, and FTIR spectroscopy were used to deduce a mechanism which consisted of the migration of hydrogen peroxide formed on the gold to the Ti sites to form hydroperoxides responsible for the epoxidation reaction. Transient XANES experiments showed that the hydroperoxides reacted at the same rate as the overall reaction, indicating that they were true intermediates in the reaction.
 

Mechanism in Homogeneous and Heterogeneous Catalytic Epoxidation
1:15 PM-4:50 PM, Sunday, August 19, 2007 Boston Park Plaza -- Whittier Rm, Oral

Division of Petroleum Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007