Thursday, November 11, 2010: 10:15 AM
251 D Room (Salt Palace Convention Center)
Reforming of oxygenated hydrocarbons (sugars, sugar alcohols, polyols, etc.) in the aqueous phase (APR) provides a promising technology to produce hydrogen from renewable resources. Pt supported on carbon is selected as one of the potential catalysts due to Pt's high selectivity to C-C bond cleavage and carbon's hydrothermal stability, but suffers from low activity. Rhenium has proven to remarkably improve the catalyst activity upon addition to Pt. In an effort to understand the role of Re in the APR process, especially under hydrothermal environment, we have employed in-situ x-ray photoelectron spectroscopy (XPS), in-situ extended x-ray absorption fine structure (EXAFS) technique, and aberration-corrected STEM imaging and x-ray analysis to investigate the structure of a PtRe/C catalyst. Our results suggest a dual-functionality of the catalyst under working conditions: modification of Pt electronic structure for enhancement of conversion and formation of ReOx for additional competing reaction pathways through C-O scission.