在CO2化金属有机框架中的邻近Zn-Zr站点
Jingzheng Zhang1, Bing An1, Zhe Li1
1Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P.R. China.
Journal of the American Chemical Society
|June 7, 2021
概括
具有Zn-O-Zr位点的金属有机框架 (MOF) 有效地催化二氧化碳 (CO2) 化为甲醇 (MeOH). 这项研究揭示了Zr4+开放点和Zn2+激活在甲醇生产中具有很高的选择性和稳定性的关键作用.
科学领域:
- 材料科学
- 催化剂
- 纳米技术
背景情况:
- 在二氧化碳 (CO2) 到甲醇 (MeOH) 的化过程中,ZrZnO材料具有协同作用.
- 了解活性场所的精确结构要求对于优化甲醇合成至关重要.
研究的目的:
- 在金属有机框架 (MOF) 中构建和描述Zn2+-O-Zr4+位点.
- 阐明控制二氧化碳化甲醇生产的结构因素.
主要方法:
- 使用ZnEt2和热处理对MOF-808进行合成后的修改.
- 用催化试验将二氧化碳化为MeOH.
- 用于结构分析的X射线吸收光谱 (XAS).
- 用温度编程的H2和CO2脱吸和H/D交换试验.
主要成果:
- 在250°C时,MOF-808-Zn催化剂达到>99%的MeOH选择性.
- 190.7 mgMeOH gZn-1 h-1 的高空间时间产量和稳定性> 100 h.
- XAS确认了Zn2+-O-Zr4+中心,而不是ZnO集群.
- 证明了H2的Zn2+激活和CO2激活开放Zr4+位点的必要性.
结论:
- 在MOF中确定的Zn2+-O-Zr4+位点对二氧化碳化为MeOH有效.
- 开放的Zr4+位点对于二氧化碳激活至关重要,可能是通过二氧化碳分解.
- MOF提供了一个对双功能催化中心的详细研究平台.
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