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采用柠檬酸法制备了CexSn1 -xO2 复合氧化物 ,并对复合氧化物的结构和还原性能进行了表征。结果表明 ,少量Sn能取代CeO2 晶格中Ce原子形成立方相的固溶体 ,并使晶胞参数变小 ;Sn超过 2 0 %时形成混合相。65 0℃焙烧的CexSn1 -xO2 复合氧化物有 3个还原峰 (α、β和γ)。α峰归属为表面Sn4 + 的还原 (～ 3 3 0℃ ) ;β峰归属为体相SnO2 和表面Ce4 + (～ 63 0℃ )的还原 ;γ峰归属为体相CeO2 的还原。焙烧温度的提高使得 β峰增强 ,α峰变弱 ,γ峰几乎不变 ;而低温焙烧有利于CexSn1 -xO2 固溶体的形成。再氧化处理对样品的还原性能有很大的影响。
The CexSn1-xO2 composite oxide was prepared by citric acid method and the structure and reduction performance of the composite oxide were characterized. The results show that a small amount of Sn can replace the Ce atoms in the CeO2 lattice to form a cubic phase solid solution and decrease the unit cell parameters. When Sn exceeds 20%, a mixed phase is formed. The CexSn1-xO2 complex oxide calcined at 65 ℃ has three reduction peaks (α, β and γ). The α peak is attributed to the reduction of surface Sn4 + (~330 ℃). The β peak is attributed to the reduction of bulk SnO2 and the surface Ce4 + (~ 63 0 ℃). The γ peak belongs to the reduction of bulk CeO2. The increase of calcination temperature leads to the increase of β peak, the decrease of α peak and the change of γ peak, while the low temperature calcination is beneficial to the formation of CexSn1-xO2 solid solution. Reoxidation has a significant effect on the reduction performance of the sample.