New experimental technique: X-ray absorption spectroscopy detector for in situ studies in the soft X-ray range (250 eV ⩽ hv ⩽ 1000 eV) under reaction conditions

Abstract

A novel tank reactor equipped with t otal electron yield (TEY) detectors was designed and constructed for in situ X-ray absorption spectroscopy (XAS) investigations in the soft X-ray range (250 eV ⩽ by ⩽ 1000 eV) under elevated pressures (up to 20 mbar) and sample temperatures (up to 1000 K). This allows, for the first time, XAS studies in the TEY mode at the K-absorption edges of the low atomic number elements like carbon, nitrogen and oxygen with high surface sensitivity. Furthermore, the gas-phase XAS and the surface-related XAS of the catalyst can be collected simultaneously in order to correlate the gas/solid reaction rate with the electronic structure of the sample surface and near-surface region. This work presents the experimental technique and the oxygen K- and copper L 2,3 X-ray absorption near-edge structures (XANES) of Cu(poly) obtained under various gas environments and at reaction temperature.