用乙醇脱水作为催化试验反应探测的Zr6O8金属有机框架节点表面的结构和动力学
Dong Yang1, Manuel A Ortuño2, Varinia Bernales2
1Department of Chemical Engineering , University of California , Davis , California 95616 , United States.
Journal of the American Chemical Society
|February 21, 2018
概括
具有Zr6O8节点的金属有机框架 (MOF) 催化乙醇脱水到乙烯. 节点上的缺陷点通过SN2机制促进了这种选择性双分子反应.
科学领域:
- 材料科学
- 催化剂
- 化学学
背景情况:
- 金属有机框架 (MOF) 是具有可调节结构的多孔材料.
- 金属氧化物集群,如Zr6O8,可以作为MOF的节点.
- 这些节点的表面空隙可以作为活跃的催化场所.
研究的目的:
- 为了阐明UIO-66和UIO-67MOF中的Zr6O8节点的化学性质.
- 确定Zr6O8节点表面上的配体.
- 为了研究这些节点的催化性能以乙醇脱水.
主要方法:
- 红外 (IR) 光谱检测,以确定表面配体.
- 核磁共振 (NMR) 光谱以描述节点的化学性质.
- 密度函数理论 (DFT) 计算以建模反应机制.
主要成果:
- 从Zr6O8节点上的合成溶剂和修饰剂中产生的已识别的配体.
- 在 473-523 K 时被证明是选择性乙醇脱水.
- DFT的计算显示,节点连接器断裂或缺陷点对于催化非常重要.
结论:
- 在UiO-66和UiO-67中Zr6O8节点表现出选择性催化活性以形成乙烯.
- 催化是通过特定的节点链接器相互作用或缺陷促进的SN2机制进行的.
- 了解节点化学是设计选择性催化MOF的关键.
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