The effect of gold addition on the catalytic performance of copper manganese oxide catalysts for the total oxidation of propane

Abstract

Mixed copper manganese oxide catalysts (Hopcalite) have been studied for the total oxidation of propane, as a model for hydrocarbon volatile organic compound emission control. Catalysts were prepared using coprecipitation with and without gold. Calcination temperature influenced the catalyst activity and those prepared at 300°C were the most active. Characterization showed that the catalysts had a nanowire-type morphology, and for those containing gold it was present as metallic particles occluded within the nanowires. The incorporation of gold into the catalyst enhanced the activity for propane conversion, but the presence of gold did not noticeably enhance the light-off activity. Although the addition of gold enhanced the propane total oxidation activity, the amount of gold incorporated did not greatly influence the catalytic activity. Significantly the Hopcalite-based catalysts, particularly those containing gold, showed total propane oxidation activity far greater than palladium-based catalysts. The improved activity on the incorporation of gold into Hopcalite is related to the reducibility of the catalysts, which is increased by gold addition. The gold-containing catalyst demonstrated stable activity through cycling and with time-on-line and it exhibited increased stability over the equivalent Hopcalite catalyst.