关键词: 共沉淀,    ,  铜铬,    ,  酸性质,    ,  模型

Abstract: A series of CuCr catalysts had been synthesized via conventional coprecipitation method under different experimental conditions to investigate the influence of preparation conditions on acidic properties and develop a novel way to detect the acidity. The SEM results show that acidic properties of catalysts have intimate relation with their textural structure. A model of binary CuO/Cr₂O₃ mixed oxides had been proposed on the basis of the hypotheses of Thanable and Seiyama. After analysis, it is indicated that in the amorphous catalysts, the acidic sites are provided merely by CuO and Cr₂O₃, while in the crystal samples, those composed of both the oxides themselves and increasement of B acidic sites caused by the asymmetrical mixture of CuO and Cr₂O₃, which further illustrated that with the crystal size of oxides decreasing, the particles became welldistributed, together with the decreasing of acidic properties of the catalysts and B acid ratio，and vice versa.

Key words: Coprecipitation,   , 　CuCr,    , 　Acidic properties,   , 　Model