Mild-acid-assisted thermal or hydrothermal dealumination of zeolite beta, its regulation to Al distribution and catalytic cracking performance to hydrocarbons
Mild-acid-assisted thermal or hydrothermal dealumination of zeolite beta, its regulation to Al distribution and catalytic cracking performance to hydrocarbons
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弱酸辅助β沸石热或水热脱铝及其对Al分布的调节和烃类催化裂化性能
DOI：
10.1016/j.jcat.2018.03.002
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发表时间：
2018-06
影响因子：
7.3
通讯作者：
Shen Baojian
中科院分区：
文献类型：
--
作者：
Wang Wennian;Zhang Wei;Chen Yunlei;Wen Xiaodong;Li Hao;Yuan Delin;Guo Qiaoxia;Ren Shenyong;Pang Xinmei;Shen Baojian
合成的纳米β沸石（SiO2/Al 2 O3 = 25，纳米晶尺寸为50 nm）经过酸蒸和酸煅烧两种不同的处理方法：即稀HCl水溶液处理。溶液（小于1 mol/L）处理，然后进行蒸汽处理或煅烧。这些连续的处理施加两次。研究了酸蒸和酸烧处理对β沸石不同T位骨架铝、不同类型骨架外铝（EFAL）和酸性的影响。结果表明，70%的Al被去除，Al在β沸石中的位置和状态受不同处理组合的调控。27 Al（MQ）MAS NMR、IR、XPS和XRF数据表明，酸汽蒸处理中，汽蒸占主导地位，T2、T5、T6和T7位的Al原子几乎完全被去除。更多的EFAL物种形成并迁移到沸石β的外表面。在酸煅烧处理中，通过煅烧和酸处理分步完成脱铝，T5，T6和T9位上的骨架Al原子被去除，并且形成更多的单体EFAL物种，导致更均匀的Al分布。酸焙烧和酸汽蒸处理的β沸石显示出相似的体相SiO2/Al 2 O3比，但不同的酸性分布。酸焙烧处理比酸汽蒸处理产生更多的B酸中心和更强的B酸，从而提高了正辛烷催化裂化的转化率和减压柴油催化裂化的汽油收率。
The synthesized nanoscale beta zeolites (SiO2/Al2O3= 25, nanocrystals of 50 nm) were treated by two different sequential procedures called acid-steaming and acid-calcination treatment: that is, dilute HCl aq. solution (less than 1 mol/L) treatment followed by either steaming or calcination. These successive treatments were applied two times. The effect of both acid-steaming and acid-calcination treatment of beta zeolite on framework Al at different T-sites, extra-framework Al (EFAL) of different types, and acidity was studied. It was found that nearly 70% of Al was removed in these processes, the location and state of Al in zeolite beta are regulated by different combinations of treatments.27Al (MQ) MAS NMR, IR, XPS, and XRF data showed that steaming dominated dealumination in the acid-steaming treatment, and Al atoms on T2, T5, T6, and T7 sites were almost completely removed. More EFAL species were formed and migrated to external surfaces of zeolite beta. In acid-calcination treatment, dealumination was completed stepwise by calcination and acid treatment, framework Al atoms on T5, T6, and T9 sites were removed, and more monomeric EFAL species were formed, leading to a more homogeneous Al distribution. The resultant zeolites beta treated by acid calcination and by acid steaming show similar bulk SiO2/Al2O3ratios but different acidity distributions. Acid-calcination treatment results in more Brønsted acid sites and stronger Brønsted acidity than acid-steaming treatment, leading to higher conversion inn-octane catalytic cracking and higher gasoline yield in vacuum gas oil catalytic cracking.
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DOI：
10.1016/0927-6513(93)80067-5
发表时间：
1993-07
期刊：
Microporous Materials
影响因子：
--
作者：
E. B. Lami;F. Fajula;D. Anglerot;T. D. Courières
通讯作者：
E. B. Lami;F. Fajula;D. Anglerot;T. D. Courières
DOI：
10.1016/s0144-2449(97)00103-6
发表时间：
1997-11
期刊：
Zeolites
影响因子：
--
作者：
Chun Yang;Qinhua Xuaf
通讯作者：
Chun Yang;Qinhua Xuaf
影响因子：
2.8
作者：
Jian-Ping Shen;Jun Ma;D. Jiang;E. Min
通讯作者：
Jian-Ping Shen;Jun Ma;D. Jiang;E. Min
影响因子：
3.6
作者：
Z. Musilová;N. Žilková;Sang-Eon Park;J. Čejka
通讯作者：
Z. Musilová;N. Žilková;Sang-Eon Park;J. Čejka
影响因子：
3.7
作者：
Dzwigaj, Stanislaw;Millot, Yannick;Kyriienko, Pavlo
通讯作者：
Kyriienko, Pavlo