An in situ and operando X-ray absorption spectroscopy setup for measuring sub-monolayer model and powder catalysts

J Synchrotron Radiat. 2005 Sep;12(Pt 5):675-9. doi: 10.1107/S0909049505020261. Epub 2005 Aug 16.

Abstract

A new spectroscopic cell has been designed for studying model catalysts using in situ or operando X-ray absorption spectroscopy. The setup allows gas treatment and can be used between 100 and 870 K. Pressures from 10(-3) Pa up to 300 kPa can be applied. Measurements on model systems in this particular pressure range are a valuable extension of the commonly used UHV characterization techniques. Using this setup, we were able to analyze the Au L3 EXAFS of a silica wafer covered with sub-monolayer concentrations of gold (0.05 ML). By modifying the sample holder, powder catalysts can also be analyzed under plug-flow conditions. As an example, the reduction of a Au/SiO2 powder catalyst prepared from HAuCl4 was followed.