Low-pressure methanol oxidation over a Cu(110) surface under stationary conditions: (I) reaction kinetics

The steady-state kinetics of methanol oxidation over Cu(110) have been studied in the 10−7 to 10−3 mbar range. H2, H2O, and CO2 are found in addition to the main product formaldehyde. The reactive sticking coefficient of methanol reaches 0.2. A pronounced hysteresis is observed when the temperature is cycled. Our data indicate the presence of two rate maxima, one at image and the other at image. The amplitude of the low-temperature reactivity peak decreases with increasing total pressure, vanishing beyond 10−3 mbar. High oxygen partial pressures led to a poisoning of the reaction, which was apparently caused by the inhibitory effect of high oxygen coverage on methanol adsorption.