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Abstract: Using sn_xTi_1−xO₂ as carriers, CuO/Sn_0.9Ti_0.1O₂ and CuO/Sn_0.7Ti_0.3O₂ catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn_0.9Ti_0.1O₂ and CuO/Sn_0.7Ti_0.3O₂ were examined using a microreactor-gas chromatography (GC) NO+CO reaction system and the methods of BET (Brunauer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H₂-temperature programmed reduction (TPR). The results showed that NO conversions of Sn_0.9Ti_0.1O₂ and Sn_0.7Ti_0.3O₂ were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn_0.9Ti_0.1O₂ and Sn_0.7Ti_0.3O₂ represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the γ peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (δ) of the catalysts meant that the sn_xTi_1−xO₂ mixed oxides could be reductive.

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