Low-Temperature Decomposition of Nitrous Oxide on Cs/MexCo3−xO4 (Me: Ni or Mg, x = 0–0.9) Oxides

Abstract

Mixed oxides MexCo3−xO4 (Me: Ni or Mg, x = 0–0.9) with a spinel structure were synthesized by precipitation from Me, Co nitrate solutions using (NH4)2CO3 as the precipitating agent with subsequent modification of the dry precipitate with cesium by the Pechini method and calcination. The samples were studied by XRD, TPR, and TPD methods. Their catalytic activity was studied in the low-temperature (150–350 °C) nitrous oxide decomposition process. It was shown that an increase in the degree of substitution of cobalt (x) leads to a significant decrease in the degree of crystallization of the oxides, an increase in the specific surface area, and the formation of surface weakly bound oxygen species. The highest activity was shown by the catalysts with a degree of substitution x = 0.1, especially by the nickel-substituted sample, which contained the maximum amount of weakly bound surface oxygen species. The difference in the influence of Mg and Ni on the MexCo3−xO4 properties is discussed.