Low-pressure methanol oxidation over a Cu(110) surface under stationary conditions: (II) adsorbate coverages and reactivity

The kinetics of methanol oxidation on a Cu(110) surface have been followed under stationary reaction conditions in the 10−7 to 10−5 mbar range with low-energy electron diffraction, Auger electron spectroscopy, photoelectron emission microscopy, and rate measurements. A large, 300–400 K-wide hysteresis occurs with cycling of the temperature. The (image) and c(image) structures, attributed to intermediates of the reaction, are seen only in a T-interval from 300 to image, where the reaction ignites. The surface exhibits substantial carbon coverage upon heating, but on the cooling branch the surface is largely carbon free down to image, where the surface becomes covered by C-containing adsorbates again.