The chemical heterogeneity of active surface of solid catalysts

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• 作者：Zhu Jianjun ; Jianzhong Jiang ; Lin Xiping and Zhu Yiqing
• 刊名：Journal of Materials Science
• 出版年：2000
• 出版时间：2000
• 年：2000
• 卷：35
• 期：22
• 页码：5787-5789
• 全文大小：51 KB

文摘

The chemical adsorption behaviors of three adsorbates on the Ni-W/F-Al₂O₃-SiO₂ and the supported Ni catalysts have been investigated. On the basis of fractal geometry, the roughness fractal dimension (D_r) and the chemisorption fractal dimension (D_c) of the catalysts are estimated. We use the difference between D_c and D_r to characterize the chemical heterogeneity of active sites on the catalytic surface. It is found that the chemical heterogeneity of the acid sites of the Ni-W/F-Al₂O₃-SiO₂ catalyst is very large, while it decrease with increasing of impregnating operation times in preparation of the supported Ni catalyst. After 4 times impregnation, the chemical heterogeneity of its active surface for the supported Ni catalyst is eliminated.