Direct synthesis of HZSM-5 zeolites with enhanced catalytic performance in the methanol-to-propylene reaction
Direct synthesis of HZSM-5 zeolites with enhanced catalytic performance in the methanol-to-propylene reaction
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直接合成HZSM-5沸石在甲醇制丙烯反应中具有增强的催化性能
DOI：
10.1016/j.cattod.2022.04.023
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发表时间：
2022-04
期刊：
影响因子：
5.3
通讯作者：
Min Zhou
中科院分区：
文献类型：
--
作者：
Rui Feng;Peng Zhou;Bao Liu;Xinlong Yan;Xiaoyan Hu;Min Zhou
以氢氧化氨为碱源，采用两步结晶法直接合成了HZSM-5沸石分子筛，并在470℃下考察了其在甲醇制丙烯(MTP)反应中的性能。结合体相和表面表征技术研究了结晶度、孔隙率、形貌、铝分布和酸度随实验条件的变化。结果表明，氢氧化氨对HZSM-5沸石的结晶度和晶型影响较小，而硅源和铝源对沸石的晶型和铝分布有显著影响。酸性质和铝的分布引起了MTP活性和选择性的重要变化。因此，增加HZSM-5中骨架SiO_2/Al_2O_3的比例，即降低孔道交叉处的酸密度和骨架铝物种的数量，可以通过有利于烯烃类循环反应来提高丙烯的选择性。催化剂的寿命不仅与酸密度有关，还与酸分布(或骨架铝分布)有关。
HZSM-5 zeolites were directly synthesized via a two-stage crystallization method using ammonia hydroxide as an alkaline source instead of the conventional sodium hydroxide, and their performance in the methanol-to-propylene (MTP) reaction was investigated at 470 °C. The use of ammonia hydroxide as the alkaline source can overcome the inherent drawback of requiring multiple ion exchanges for converting Na-form zeolites to NH4+-form derivatives. Bulk and surface characterization techniques were combined to study the changes in crystallinity, porosity, morphology, aluminum distribution, and acidity with the experimental conditions. It was found that ammonia hydroxide had limited effect on the crystallinity and morphology of HZSM-5 zeolites, whereas the silicon and aluminum sources affected significantly the morphology and aluminum distribution. The acid properties and aluminum distribution induced important changes in the MTP activity and selectivity. Thus, increasing the framework SiO2/Al2O3ratios in HZSM-5, in other words, reducing the acid density and the amount of framework aluminum species in the channel intersections, could improve the selectivity to propylene by favoring the olefinic-based cycle reaction. The catalyst lifetime was found to depend on not only the acid density but also on the acid distribution (or framework aluminum distribution).
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影响因子：
3.7
作者：
Rui Feng;Xinlong Yan;Xiaoyan Hu;Zifeng Yan;Jiawei Lin;Zheng Li;K. Hou;M. Rood
通讯作者：
Rui Feng;Xinlong Yan;Xiaoyan Hu;Zifeng Yan;Jiawei Lin;Zheng Li;K. Hou;M. Rood
影响因子：
3.7
作者：
Holzinger, Julian;Beato, Pablo;Skibsted, Jurgen
通讯作者：
Skibsted, Jurgen
通过比较 ZSM-5 和 ZSM-11 观察甲醇转化为烯烃时酸性沸石的催化性能与铝位点的关系
影响因子：
12.9
作者：
Wang Sen;Wang Pengfei;Qin Zhangfeng;Chen Yanyan;Dong Mei;Li Junfen;Zhang Kan;Liu Ping;Wang Jianguo;Fang Weibin
通讯作者：
Fang Weibin
影响因子：
--
作者：
Li-li Yu;Shengjun Huang;S. Miao;Fucun Chen;Shuang Zhang;Zhenni Liu;Sujuan Xie;Longya Xu
通讯作者：
Li-li Yu;Shengjun Huang;S. Miao;Fucun Chen;Shuang Zhang;Zhenni Liu;Sujuan Xie;Longya Xu
影响因子：
5.2
作者：
Feng, Rui;Wang, Xixi;Rood, Mark J.
通讯作者：
Rood, Mark J.