First-principles study of N2O decomposition on (001) facet of perovskite LaBO3 (B = Mn, Co, Ni)

Abstract In this work,density functional theory (DFT) was used to investigate the N2O molecule decomposition mechanism on LaBO3 (B = Mn, Co, Ni) perovskites in thermodynamics and kinetics,and the decomposition of two N2O molecule was divided into two processes.For thermodynamics,the DFT calculation results showed that the energy barriers in LaMnO3, LaCoO3, and LaNiO3 were about 0.99 eV, 1.65 eV and 2.42 eV in the first process and 0.94 eV, 1.82 eV and 2.64 eV in the second process,and the barriers energy in LaMnO3 were smaller than those on the others,so it showed the best catalytic performance in N2O molecule decomposition.The O2 molecule desorption energy were 0.5 eV, 0.3 eV and 0.19eV in LaMnO3, LaCoO3 and LaNiO3,so the low desorption energy made O2 molecules detach from the surface easily to complete the entire reaction process.In addition,the calculation results of the kinetic reaction rate coefficient(k) also proved that LaMnO3 had extremely high kinetic activity for dynamics, and the O2 molecules desorption reaction was not a rate-controlled process.Therefore, LaMnO3 had high catalytic activity for the N2O molecules decomposition reaction in terms of thermodynamics and kinetics,and these results increased our understanding of the mechanism of NOx decomposition on perovskites.