In situ studies of nanoparticles under reaction with sulfur by XAS

In this paper, we present the first results obtained with a reactor especially designed for in situ studies by using the X-ray absorption spectroscopy technique. The reactor was used to monitor modifications in the chemical environment of a selected atom in the catalyst under reactive conditions. We have investigated the Pt atoms in catalysts consisted of PtPd and Pt nanoparticles prepared in the presence of BMI·PF6 ionic liquid. Our main purpose was to study the changes in the electronic and structural properties as the catalyst was submitted to reduction and sulfidation reactions. The modifications in the absorption spectra at the Pt L3 edge were clearly ascertained to both processes.