【摘 要】
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The Na2CO3-modiifed HZSM-5 zeolites were further treated by tetrapropylammonium hydroxide (TPAOH) solu-tion. The effect of TPAOH concentration on the secondary
【机 构】
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School of Material and Metallurgy, Northeast University, Shenyang 110004;School of Petrochemical Eng
论文部分内容阅读
The Na2CO3-modiifed HZSM-5 zeolites were further treated by tetrapropylammonium hydroxide (TPAOH) solu-tion. The effect of TPAOH concentration on the secondary crystallization process was investigated. The resulting samples were characterized by a complementary combination of X-ray diffraction, N2 adsorption/desorption, scanning electron microscopy, X-ray lfuorescence spectroscopy, XPS, 27Al and 29Si magic-angle spinning nuclear magnetic resonance spec-troscopy, BET and temperature-programmed desorption techniques. The results showed that the secondary crystallization of the HZSM-5 zeolite could result in migration of non-framework species from the intal channels to the zeolite surface and their transformation into framework species. The catalytic activity of these modiifed samples for thiophene alkylation was evaluated. Both the activity and stability of the catalysts were improved after secondary crystallization.
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