XPS CHARACTERIZATION OF A COMMERCIAL Cu/ZnO/ Al₂O₃ CATALYST: EFFECTS OF OXIDATION, REDUCTION AND THE STEAM /REFORMATION OF METHANOL.

X-ray photoelectron spectroscopy (XPS) is used to characterize the surface region of a commercial Cu/ZnO/Al//2O//3 (33/66/1 wt percent) catalyst. A systematic study of the effects of oxidation, reduction, and the steam reformation of methanol on the oxidative state of the Cu component is presented. The Zn XPS features show no changes due to the various treatments. Peak fitting procedures were developed to quantitate the Cu oxidation states on the basis of the XPS Cu 2P//3/////2 main and satellite features. After oxidation in pure O//2 at 300 degree C, all Cu exists as Cu** plus **2. The Cu/Zn ratio changes from 0. 28 to 0. 37 as a result of this oxidation, in comparison to the ratio in the catalyst as-received.