کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
40842 | 45868 | 2012 | 4 صفحه PDF | دانلود رایگان |
Specific surface area based on the BET method in N2 adsorption has historically posed poor correlation with olefin polymerization activity of heterogeneous Ziegler-Natta (ZN) catalysts. We have investigated the validity of the BET surface area for ZN catalysts based on the αS-plot method, where non-porous core–shell MgO/MgCl2/TiCl4 catalysts were used as a reference material. The αS-plots for typical industrial ZN catalysts clarified the presence of two classes of micropores and resultant difficulty to isolate a multilayer adsorption region for the BET method. The results cast doubt on the application of the BET method to evaluate the surface area of heterogeneous ZN catalysts.
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► Validation of the BET surface area of Ziegler-Natta catalysts based on the αS-plot method.
► Non-porous core–shell MgO/MgCl2/TiCl4 catalysts were used as reference.
► Micropore filling heavily overlaps with a multilayer adsorption region for the BET analysis.
► The BET surface area is questionable for typical Ziegler-Natta catalysts.
Journal: Applied Catalysis A: General - Volumes 437–438, 26 September 2012, Pages 24–27