Identification of nickel sulfides on Ni–YSZ cermet exposed to H 2 fuel containing H 2S using Raman spectroscopy

Abstract

Ni–YSZ cermet was exposed to hydrogen containing different concentrations of H 2S to identify the phases formed under various conditions using Raman spectroscopy and X-ray diffraction (XRD). For Ni–YSZ samples exposed to hydrogen containing 100 ppm H 2S at 727 °C for 5 days, thermodynamic calculations indicate that Ni–YSZ would be stable and XRD analysis was unable to detect any changes. However, the vibration modes of Ni 3S 2 were detected using Raman spectroscopy, suggesting that Raman spectroscopy could be a powerful tool for in situ study of sulfur poisoning of SOFC anodes. For Ni–YSZ cermet exposed to hydrogen containing 10% H 2S at 950 °C for 5 days, Ni was converted to nickel sulfide, and vibration modes of NiS were detected using Raman spectroscopy.