Promoting the activity and selectivity of high surface area Ni-Ce-O mixed oxides by gold deposition for VOC catalytic combustion

Gold supported on nickel cerium oxide catalysts (Ni–Ce–O) have been studied for the total oxidation of propane, as a model for hydrocarbon volatile organic compound emission control. High surface area Ni–Ce–O catalysts were synthesized using a very simple evaporation method, where cerium and nickel salts were evaporated in the presence of a mixture of methanol and oxalic acid. Gold catalysts were prepared following a deposition–precipitation method. A very efficient catalyst for the oxidation of propane, in terms of both activity and selectivity, was obtained. This high activity has been related to the high surface area of the catalyst (and therefore to the presence of more active sites available), a high reducibility of Ni-sites and a low strength of the Ni–O bond. Additionally, all the gold catalysts tested are highly selective towards CO2 (close to 100%), in contrast to gold-free catalysts