Solid-State NMR Investigations of Supported Ionic Liquid Phase Water-Gas Shift Catalysts: Ionic Liquid Film Distribution vs. Catalyst Performance
Solid-State NMR Investigations of Supported Ionic Liquid Phase Water-Gas Shift Catalysts: Ionic Liquid Film Distribution vs. Catalyst Performance
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DOI：
10.1002/ceat.201200025
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发表时间：
2012-08-01
影响因子：
2.1
通讯作者：
Szesni, Normen
中科院分区：
文献类型：
--
作者：
Haumann, Marco;Schoenweiz, Andreas;Szesni, Normen
通过固态核磁共振研究了负载型离子液体相（SILP）催化剂中的离子液膜分布。将[EMIM][NTf2]固定在硅胶100载体上，负载量在0和40％vol.-％之间。 1H NMR 信号表明载体表面硅烷醇基团与离子液体质子之间的交换过程。当离子液体负载量低于10％体积时，离子液体岛似乎形成，而当负载量较高时，实现了载体的完全覆盖。基于 NMR 的薄膜模型通过使用具有不同离子液体负载量的已知 SILP 催化剂的气相水煤气变换实验得到了证实。在高离子液体负载量下，催化剂的活性由于孔堵塞而降低。 NMR 技术为薄膜形成和分布提供了简单可靠的数据，并可在未来优化 SILP 催化剂。
The ionic liquid film distribution in supported ionic liquid phase (SILP) catalysts has been studied by solid-state NMR. [EMIM][NTf2] was immobilized onto silica gel 100 support with loadings between 0 and 40?vol.-%. The 1H NMR signals indicated an exchange process between the support's surface silanol groups and the protons of the ionic liquid. At ionic liquid loadings below 10?vol.-%, islands of ionic liquids seemed to form, whereas at higher loadings complete coverage of the support was achieved. The NMR-based film model was confirmed by gas phase water-gas shift experiments using known SILP catalysts with different ionic liquid loadings. At high ionic liquid loading, the activity of the catalyst decreased due to pore blocking. The NMR technique provided easy and reliable data for film formation and distribution and allows for optimization of SILP catalysts in the future.