Solid-state NMR studies of the acidity of functionalized metal-organic framework UiO-66 materials
Solid-state NMR studies of the acidity of functionalized metal-organic framework UiO-66 materials
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功能化金属有机骨架 UiO-66 材料酸性的固态核磁共振研究
DOI：
10.1002/mrc.4923
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发表时间：
2019
影响因子：
2
通讯作者：
Feng Deng
中科院分区：
文献类型：
--
作者：
Jing Tang;Shenhui Li;Yueying Chu;Yuqing Xiao;Jun Xu;Feng Deng
金属有机骨架的酸强度对其催化反应中的活性和选择性等催化性能起着关键作用。采用固态核磁共振结合 2-13C-丙酮和吡啶-d5 等探针分子来表征 UiO-66-X (X = ‐H, ‐2COOH, ‐SO3H) 的酸强度。结果发现，引入官能团后，UiO-66-2COOH和UiO-66-SO3H的酸强度较母体UiO-66显着增强，前者与H-ZSM-5沸石相似，后者略强于前者。尽管可以通过改变多元功能化 UiO-66-X 中的相对比例来有效地改变酸密度，但与酸性同链对应物相比，MTV-UiO-66-X 中的酸强度没有明显变化。通过理论计算进一步证实了UiO-66-SO3H和UiO-66-2COOH的酸强度。
The acid strength of metal–organic frameworks plays a key role in their catalytic performance such as activity and selectivity during catalytic reactions. Solid‐state nuclear magnetic resonance in combination with probe molecules including 2‐13C‐acetone and pyridine‐d5was employed to characterize the acid strength of UiO‐66‐X (X = ‐H, ‐2COOH, ‐SO3H). It was found that after introduction of the functional groups, the acid strength of UiO‐66‐2COOH and UiO‐66‐SO3H is considerably enhanced compared with that of parent UiO‐66, with that of the former being similar to that of zeolite H‐ZSM‐5, and with that of the latter being slightly stronger than that of the former. Even though the acid density can efficiently be modified through changing the relative ratio in multivariate functionalized UiO‐66‐X, no significant alternation for the acid strength could be discerned in the MTV‐UiO‐66‐X compared with acidic same‐link counterpart. Theoretical calculations were employed to further confirm the acid strength of UiO‐66‐SO3H and UiO‐66‐2COOH.