On the optimal Cs/Co ratio responsible for the N2O decomposition activity of the foam supported cobalt oxide catalysts

Abstract

Structured foam catalysts for N2O decomposition containing Co and Cs were prepared via conventional and organic-assisted impregnation method (acetic acid, citric acid, glycerol, glycine, urea). Organic-assisted impregnation caused higher abundance of smaller particles and different faceting. Glycerol usage leads to increase of specific rate constant for N2O decomposition, urea leads to its decrease. The optimal amount of Cs in Co3O4deposited on the foam was 2–3 times higher than in the bulk Co3O4-Cs due to the dispersion of part of the Cs species over the bare support. The use of glycerol caused a better surface coverage by spinel phase, thus leaving less space for spreading the cesium on the support instead of on the spinel phase. The positive effect of glycerol on the performance of the catalysts with optimized cesium content was attributed to refaceting of the spinal nanocrystals, and greater resistance of the (100) planes to gaseous NO/H2O contaminates.