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论文类型：期刊论文

发表时间：2011-02-02

发表刊物：CATALYSIS TODAY

收录刊物：Scopus、SCIE、EI

卷号：160

期号：1

页面范围：179-183

ISSN号：0920-5861

关键字：Shape-selective; Nano-scale HZSM-5; Pt; Hydrogenation; Stability

摘要：Shape-selective methylation of toluene (T) with methanol (M) was carried out in continuous flow fixed-bed reactor over Pt-modified nano-scale HZSM-5 catalysts, and excellent stability was obtained. Even after 500 h on stream, toluene conversion of 22.0-23.0% was achieved simultaneously with the para-selectivity of >98%. The presence of Pt on the modified nano-scale HZSM-5 solves the apparent paradox of high para-selectivity and low stability. Catalysts were characterized by using X-ray diffraction (XRD), temperature programmed desorption of ammonia (NH(3)-TPD), Pyridine IR (Py-IR), TG-SDTA, scanning electron microscope (SEM), etc. The results show that significant enhancement in stability over Pt-modified nano-scale HZSM-5 catalysts is mainly due to good hydrogenation properties of Pt particles. (C) 2010 Elsevier B.V. All rights reserved.