摘要：To understand the dispersion behavior of metal oxides on composite oxide supports and with the expectation of developing more feasible catalysts for soot oxidation,CuO/La_(2)Sn_(2)O_(7)samples containing varied CuO loadings were fabricated and characterized by different techniques and density functional theory *** these catalysts,a spontaneous dispersion of CuO on the La_(2)Sn_(2)O_(7)pyrochlore support formed,having a monolayer dispersion capacity of 1.90 mmol CuO/100 m^(2) La_(2)Sn_(2)O_(7)*** loaded below this capacity,CuO exists in a sub-monolayer or monolayer state.X-ray photoelectron spectroscopy(XPS),Raman spectroscopy,and Bader charge and density of states analyses indicate that there are strong interactions between the sub-monolayer/monolayer CuO and the La_(2)Sn_(2)O_(7)support,mainly through the donation of electrons from Cu to Sn at the B-sites of the *** contrast,Cu has negligible interactions with La at the *** suggests that,in composite oxide supports containing multiple metals,the supported metal oxide interacts preferentially with one kind of metal cation in the *** Raman,in situ diffuse reflectance infrared Fourier transform spectroscopy,and XPS results confirmed the formation of both O2^(-)and O2^(2-)as the active sites on the surfaces of the CuO/La_(2)Sn_(2)O_(7)catalysts,and the concentration of these active species determines the soot combustion *** number of active oxygen anions increased with increase in CuO loading until the monolayer dispersion capacity was *** the monolayer dispersion capacity,microsized CuO crystallites formed,and these had a negative effect on the generation of active surface oxygen *** summary,a highly active catalyst can be prepared by covering the surface of the La_(2)Sn_(2)O_(7)support with a CuO monolayer.