Studies on the catalytic decomposition of N2O on rare earth cuprates of the type Ln2CuO4

Abstract

The kinetics of nitrous oxide decomposition between 400 and 480 °C at two different initial pressures namely, 50 and 200 Torr over a series of isostructural rare earth cuprates (Ln2CuO4) is described. The kinetics obeyed a rate expression corresponding to strong inhibition by oxygen at both the initial pressures, except on La2CuO4. The observed higher activation energy values at 50 Torr initial pressure as compared to 200 Torr has been understood in terms of the importance of O(ads) species migration on the surface. A multicenter type of adsorption of N2O over a cluster of Ln---O---Cu on these surfaces could account for the various observations made in the present investigation. The operation of compensation effect and correlation between the activation energy for the reaction and (i) Ea for conduction, (ii) lattice parameter suggested the importance of the electron transfer step in the kinetics of decomposition reaction.