FeOx -supported Au catalysts prepared by co-precipitation (CP) were investigated for catalytic HCHO oxidation. The applied calcination temperature was found to greatly influence both the chemical prop- erties and microstructure of the catalysts. Characterization using XRD, H2 -TPR and XPS suggested that lower calcination temperature improves the reducibility of the catalysts, and favors the presence of sur- face hydroxyl groups. Consequently, an Au/FeOx catalyst calcined at 200 ◦ C afforded 100% conversion of HCHO into CO2 and H2 O at room temperature and under humid air. In situ DRIFTs studies suggested that the moisture was essential for deep oxidation of the formate intermediates into CO2 and H2 O, this being the rate limiting step for catalytic HCHO oxidation.