Influence of the pretreatment conditions on the performances of CeO2-supported gold catalysts in the catalytic wet air oxidation of carboxylic acids

Two series of ceria-supported gold catalysts (1 and 4 wt.% Au) were prepared by deposition–precipitation with urea. Depending on the gold loading, the pretreatment of the Au/CeO2 catalysts (calcination in air vs. reduction in hydrogen) had a great influence on the oxidation state of gold, and in turn, on the activity of the Au/CeO2 catalysts in the catalytic wet air oxidation (CWAO) of model carboxylic acids. The higher the fraction in metallic gold is, the better the catalytic performances are.

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► Well-dispersed Au/CeO2 catalysts were prepared by deposition–precipitation with urea.
► Reduction of the gold phase is crucial for the activity in the CWAO reaction.
► A synergetic effect between gold and ceria was evidenced.
► Au/CeO2 catalysts performed better than TiO2 or ZrO2-supported Pt or Ru catalysts.