Selective catalytic oxidation of ammonia into nitrogen over PCH modified with copper and iron species

Abstract

Porous clay heterostructures (PCH) obtained on the basis of the synthetic saponite was used as a catalytic support for the deposition of transition metal (Cu, Fe) oxides. Transition metal oxides were introduced into the parent as well as ammonia treated PCH support by the ion-exchange method. The obtained catalysts were characterized with respect to their textural parameters (BET), composition (EPMA), chemical nature of the introduced transition metal species (UV–vis–DRS) and surface acidity (NH 3-TPD, FTIR). The modified PCH materials were tested as catalysts for the selective oxidation of ammonia to nitrogen and water. The studied catalysts have shown a very high selectivity towards N 2, which did not drop below 90% in a large studied temperature range (150–550 °C). However, the Cu-containing samples were active at temperatures significantly lower than PCH modified with iron.