Co-Mn-Al hydrotalcite type solids were synthesized as precursors of catalysts for the total oxidation of toluene in air. For the as-prepared solids, XRD measurements indicate the coexistence of hydrotalcite and MnCO 3 phases. When calcination is performed at 500°C, different mixed oxides are found as a function of Co:Mn molar ratio and preparation method, and very high specific surface areas were obtained for the Co-Mn solids. The comparison of catalytic activities in the presence of calcined hydrotalcites with those in the presence of calcined hydroxides evidences the superiority of the first oxides due to their higher reducibility. Co-Mn-Al nano-oxides synthesized using hydrotalcite type solids as precursors, are very promising candidates for the substitution of noble metal based solids.

Co-Mg-Al hydrotalcite type solids were synthesized as precursors of catalysts for the total oxidation of toluene. After calcination at 500°C, different mesoporous mixed oxides were obtained with high specific surfaces. The comparison of the catalytic activities of the calcined hydrotalcites with those of calcined hydroxides evidenced the superiority of the first oxides explained meanly by higher specific surfaces and more easily reducible particles. DRIFT ''operando'' allowed to follow the oxidation reaction and the formation of light coke and carbonate species.

X6Al2HT hydrotalcites, where X represents Fe, Cu, Zn, Ni, Co, Mn or Mg, were synthesized as precursors of catalysts for the toluene and CO total oxidation reactions. Specific area, Fourier transformed infrared spectroscopy analysis, XRD measurements and Thermal analysis of these dried solids were performed. After calcination at 500 °C, different mixed oxides were obtained. The structural analysis (XRD, FTIR) and specific areas of these solids were done. Concerning the total oxidation of toluene, the best activity is obtained with Mn6Al2HT catalyst with T50 at 249 °C. X6Al2 nano‐oxides synthesized using hydrotalcite‐type solids as precursors, are then very promising candidates for an utilisation as CO and VOC oxidation catalysts. The nature of bivalent cation in these compounds is essential for the efficacy of the catalyst.

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