"Seeing is believing - Novel in situ techniques for studies of model catalysts"
Who: Johan Gustafson, Div. of Synchrotron Radiation Research, Lund University, Sweden
Place: Donostia International Physics Center (DIPC).Paseo Manuel de Lardizabal, 4, Donostia
Date: Thursday, 18 September 2014, 10:45
Motivated mainly by catalysis, gas-surface interactions between single crystal surfaces and molecules has been studied for decades. Although, most of these studies have been performed in unrealistically well-controlled environments, they form the basis for the present day understanding of catalysis. We have in recent years explored the possibilities to perform experiments at conditions closer to those of a technical catalyst, in particular at increased pressures. In this contribution, results from catalytic CO oxidation over Pd and Rh single crystal surfaces using high pressure X-ray photoeelectron spectroscopy (HPXPS), planar laser induced fluorescence (PLIF), and high energy surface X-ray diffraction (HESXRD) will be presented.
Armed with structural knowledge from ultra-high vacuum experiments, the presence of adsorbed molecules and gas-phase induced structures can be identified, and related to changes in the reactivity and/or to reaction induced gas-flow limitations. The strength and weaknesses of the experimental techniques will be discussed.