New opportunities in soft X-ray absorption to characterise the adsorbate bonding

Abstract

A useful and necessary step to understand the complexity of catalysis is to first study the simple prototype systems which involve elements active in such reactions. Studies throwing light on gas–metal interaction are of vital importance. The X-ray absorption spectroscopy can provide vital information for catalysis as one probes the system on a very local scale. We present state of the art surface EXAFS measurements of carbon, nitrogen and oxygen adsorbed on well characterised metal surfaces (Ni and Cu). The present contribution highlights from experimental measurements supported by improved theoretical calculations that temperature and angular dependent studies are essential for a reliable structural analysis and to gain an insight into absorbate–substrate bonding and kinetics. The low Z metal systems were found suitable to detect unambiguously the photoelectron backscattering by interstitial charge densities.