INOR 228

Spectroscopic investigation of trimethyl gallium reactions on silica and HZSM-5

Ziyad Taha, Department of Chemical Engineering, University of California Santa Barbara, UCSB, Santa Barbara, CA 93106-5080, Samuel D. Fleischman, sfleischman@chem.ucsb.edu, Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA 93106-9510, Eric Deguns, Department of Chemistry and Biochemistry, University of California Santa Barbara, University of California Santa Barbara, Santa Barbara, 93106-9510, Swarup Chattopadhyay, Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, and Susannah L. Scott, sscott@engineering.ucsb.edu, Departments of Chemical Engineering and Chemistry, University of California, Santa Barbara, Santa Barbara, CA 93106-5080.

Gallium dispersed on ZSM-5 catalyzes the dehydro-aromatization of alkanes and the selective reduction of nitrogen oxides by hydrocarbons. Trimethyl gallium has been used to make a uniform dispersion of gallium on both ZSM-5 and silica, in order to facilitate study of the structure of the active sites. Cryogenic EXAFS spectra, corroborated by DFT calculations, indicate dimethylgallium sites form oxygen-bridged dimers in ZSM-5 as well as on a silica surface pretreated at 500 ^oC. This finding has implications for proposed mechanisms of C-H activation, since earlier models assumed that gallium sites were isolated.

Inorganic Catalysts
7:00 PM-10:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Inorganic Chemistry

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