A comparative study of TiO2-supported and bulk Co–Mn–Al catalysts for N2O decomposition

Abstract A series of Co–Mn–Al/TiO 2 catalysts with different Co + Mn loading (5–24 wt.%) was prepared by impregnation of TiO 2 support. Bulk Co–Mn–Al mixed oxides were prepared by different methods. The prepared catalysts were characterized by chemical analysis, surface area measurement, temperature programmed techniques (TPR, TPD) and tested for N 2 O catalytic decomposition. TiO 2 acted only as a catalytic support and did not contribute to the catalytic activity. The N 2 O conversion over TiO 2 -supported Co–Mn–Al catalysts was increasing with Co + Mn loading, and was proportional to the amount of easily reducible components. Comparing the catalysts with identical amount of active components, the highest catalytic activity was achieved on the calcined precursors having carbonates in their molecules (layered double hydroxides Co–Mn–Al-HT-ex and Co–Mn–Al-carb), the lowest one on the calcined Co–Mn–Al nitrates due to the lower surface area, less advantageous porous structure and worse reducibility.