Oxygen on iron oxide: Effect on the selective oxidation of butane

The effect of preadsorbed and gas phase oxygen on the selective oxidation of butene to butadiene on α-iron oxide was investigated using adsorption-desorption and pulse reaction technique. It was found that irreversibly adsorbed oxygen did not affect the butene oxidation reaction. However, the presence of gas phase oxygen significantly reduced the production of butadiene and increased the production of carbon dioxide. This decrease in butadiene production was due to the high reactivity of adsorbed butadiene precursors toward weakly adsorbed oxygen. However, these butadiene precursors were not reactive toward nitrous oxide. Therefore, under steady-state conditions, the rate of production of butadiene is determined by the competition between the desorption of butadiene and the degradation of the precursors by oxygen.