Controlling the microstructure of MFI zeolites with Mg(OH)(2) nanocrystals to improve their catalytic performances
Controlling the microstructure of MFI zeolites with Mg(OH)(2) nanocrystals to improve their catalytic performances
复制标题
用Mg(OH)(2)纳米晶控制MFI沸石的微观结构以提高其催化性能
DOI：
10.1039/c4ra08277j
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发表时间：
2015
期刊：
影响因子：
3.9
通讯作者：
Li Baojun
中科院分区：
文献类型：
--
作者：
Wei Huijuan;Zhang Ning;Zhao Tian;Liu Yangqing;Wen Yiqiang;Wang Xiangyu;Li Baojun
分子筛晶体的微观结构和形貌的控制将对其催化性能产生重大影响。本文以纳米氢氧化镁为催化剂，在水热条件下合成了钛硅沸石-1(TS-1)和硅沸石-1(S-1)晶体。用X射线衍射仪、透射电子显微镜、傅立叶红外光谱和氮气吸附等手段对TS-1和S-1的结构进行了表征。氢氧化镁纳米颗粒的引入使合成的TS-1和S-1分子筛具有更加粗糙的表面，并通过附着在表面或包裹在TS-1和S-1晶体内部而产生一些空洞和狭缝。氢氧化镁纳米颗粒对TS-1和S-1的结晶度、微观结构和形貌也有较好的影响和修饰作用。将合成的TS-1和S-1分子筛分别用于环己酮氨化和气相Beckmann重排反应。当氢氧化镁的添加量为10wt%时，这两个反应的催化性能最好。在MFI沸石合成溶液中加入适量的氢氧化镁纳米碳酸酯，可提高催化剂的催化性能。
Control of the microstructure and morphology of molecular sieve crystals will significantly affect their catalytic performances. In this paper, titanium silicalite-1 (TS-1) and silicalite-1 (S-1) crystals were synthesized under hydrothermal conditions in the presence of Mg(OH)2 nanocrystals (NCs). XRD, TEM, FT-IR, and N2 adsorption were used to characterize the structure of TS-1 and S-1 crystals. The introduction of Mg(OH)2 NCs endow the as-synthesized TS-1 and S-1 with a much more rugged surface and some voids and slits via attachment onto the surface or entrapment inside TS-1 and S-1 crystals. The crystallinity behavior, microstructure and morphology of TS-1 and S-1 also are effectively affected and modified by the presence of Mg(OH)2 NCs. The obtained TS-1 and S-1 crystals were examined as catalysts for the cyclohexanone ammoximation and vapor phase Beckmann rearrangement of cyclohexanone oxime, respectively. The highest catalytic performances of the two reactions had been obtained when the Mg(OH)2 additive amount was 10 wt%. The catalytic performance was improved when the appropriate amount of Mg(OH)2 NCs was introduced into the MFI zeolite synthesis solution.