Investigation of Au/hydrotalcite catalysts for toluene total oxidation

X6Al2HT hydrotalcites, where X represents Ni, Co, Mn or Mg, have been investigated before and after gold deposition for toluene and CO total oxidation reactions. Specific area and XRD measurements of these solids have been done. No change in the structure of the hydrotalcite support due to the introduction of gold is detected for the Co6Al2HT and Mn6Al2HT support. However the deposition of gold on these oxides has a beneficial effect on the activity. Concerning the total oxidation of toluene, the best activity is obtained with Au/Mn6Al2HT catalysts with a T50 at 240 °C. However catalytic behaviour of Au/X6Al2HT catalysts in oxidation of toluene depends mainly on the nature of the support: no clear correlations have been observed between catalytic properties and the average size of the Au particles.