The use of copper catalysts for the selective reduction of NO with methanol

A series of co-precipitated Cu-ZrO₂ catalysts which have previously been shown to be very effective for the steam reforming of methanol have been shown to be active and selective catalysts using methanol as reductant when tested in the presence of excess oxygen. They are also largely resistant to the presence of water and are only partially poisoned by the presence of SO₂. When no oxygen is admitted to the test gas, all the catalysts still convert NO using methanol as reductant but the product now contains other N-containing molecules. When the oxygen concentration was adjusted so that, together with the NO, it effectively balanced the methanol content of the feed gas, all the catalysts gave exceptionally high selectivities and conversions to N₂, effectively 100% in both cases.