Raman study on methanol partial oxidation and oxidative steam reforming over copper

In situ Raman spectra of copper surfaces during the catalytic partial oxidation of methanol and methanol oxidative steam reforming have been measured and analysed. Raman measurements reveal that if methanol is present in the surrounding gas phase the ratio of quantities of CuO and Cu2O at the surface of the catalysts decreases at lower temperature. From changes in relative intensity of the band at about 220 cm−1, which is symmetry forbidden and is interpreted as an indicator of poor crystallinity and non-stoichiometry of Cu2O, we noticed that the defect density in crystal lattices of Cu2O at the surfaces of catalysts is significantly different for various reaction conditions. Methoxy species were detected as intermediates via characteristic ν(C–O) Raman band at 1070 cm−1.