Deep core level hard X-ray photoelectron spectroscopy for catalyst characterization

Heterogeneous catalysts are the crucial element for many catalytic processes. In most of the cases, the pivotal structure consists of catalytic metals/alloy particles supported by oxides. Knowledge of the interaction between metal and oxide is central to understand the structure-performance relationship of such systems. X-ray photoelectron spectroscopy provides access to the chemical-physical properties of metal and oxide interface as well as polarization effects. The results are usually derived from changes of the measured binding energies based on initial state analysis. We propose to extend the analysis using photoelectron as well as Auger transition to include final state effects (Wagner/Hohlneichner plots). This gives additional information on the specific chemical neighborhood of the excited atom. Three archetypal systems are investigated by hard X-ray photoelectron spectroscopy (HAXPES) to introduce two approaches to this analysis for the most common support elements Al and Si.