Decomposition of ammonia over a catalyst consisting of ruthenium metal andcerium oxides supported on Y-form zeolite

Ammonia decomposition proceeds at 300 degrees C over a catalyst consisting of ruthenium metal and CeO2 highly dispersed on Y-form zeolite. The catalys t, Ru-CeO2/YZ, is highly active for NH3 decomposition under conditions at w hich Y-form zeolite and CeO2 do not work. The decomposition rate is first o rder in ammonia. The initial rate of nitrogen adsorption supports the decom position mechanism involving a rate-limiting step in dinitrogen desorption. Moreover, the load of ruthenium particles on CeO2/YZ catalyst makes an inh ibition of the decomposition rate by hydrogen less strong. IR spectra for t he catalyst indicate that the ammonia decomposition proceeds via the format ion of the intermediate species, such as Ru-NH3, Ru-NH2, Ru-N-2 and Ru-H on the surface of ruthenium. The adsorption of hydrogen and XRD data support the idea that ruthenium is highly dispersed in the Ru-CeO2/YZ (C) 2000 Else vier Science B.V. All rights reserved.