Honeycomb supported perovskite catalysts for ammonia oxidation processes

Pechini route (M.P. Pechini. U.S. Patent no. 3,330,697 (1967)) was used for supporting perovskite – like systems LaBO3 (B = Mn, Fe, Co, Ni, Cu) on thin-wall (0. 35 mm) cordierite honeycomb support with low thermal expansion coefficient to prepare stable to thermal shocks supported catalysts for high-temperature processes of ammonia oxidation into NO in nitric acid production. In this preparation route, perovskites (2–6%) have nearly uniform distribution in the walls as well as form surface grainy perovskite layer 2–3 μm thick that may be also important for the high temperature processes occurring at short contact times. Cordierite supported lanthanum manganite and cobaltite are the most active in the reaction of ammonia oxidation into NO especially when supported twice or on a secondary sublayer (Ln2O3, ZrO2, MeO, LaBO3).