In situ PK-edge XANES spectra of Pt free bare Kapton and planar Pt in contact with 5 mol dm–3(5 M) H3PO3at (top) 75 C and (bottom) 25 C, both measured at the OCP. The 2D chemical structures in the graph correspond to the two tautomeric forms of H3PO3: the pyramidal form (at 75 C) and the tetrahedral form (at 25 C). The solid curves represent the average spectra of three measurements at different sample positions, with the shaded regions corresponding to the respective standard deviations of the individual measurements from the mean. An increase in the spectral weight corresponding to P compounds with the oxidation state of (+5) is observed in the XANES recorded at higher temperatures (both Pt free Kapton and planar Pt) compared to the lower temperature. At the higher temperature, negligible spectral change is observed between Kapton and planar Pt.
