Ceria-zirconia supported Au as highly active low temperature Water-gas shift catalysts

Au/CeZrO4 catalysts have shown very low temperature activity for the WGS reaction. Characterisation of the as-prepared catalysts shows An is present primarily as isolated Au3+ atoms. It has been found that a higher proportion of Au3+ present in the as-prepared catalyst leads to a higher WGS activity, although under reaction conditions reduction to Au-0 is observed. Use of TPR and iso-thermal H2O re-oxidation has shown that An reacts with H2O at lower temperatures than an equivalent Pt/CeZrO4 catalyst, indicating that H2O activation is key in the onset of low temperature WGS activity.