可逆CO结合使可调节的CO/H2和CO/N2分离能够在金属有机框架中与暴露的双价金属离子相结合
Eric D Bloch1, Matthew R Hudson, Jarad A Mason
1Department of Chemistry, University of California , Berkeley, California 94720, United States.
Journal of the American Chemical Society
|July 8, 2014
概括
六个金属有机框架 (MOF) 显示了可逆一氧化碳 (CO) 结合的高容量. 这些MOF为冷蒸提供了一个有希望的固体吸附剂替代方案,用于从工业气体中分离CO.
科学领域:
- 材料科学 材料科学 材料科学
- 无机化学 无机化学
- 物理化学 物理化学
背景情况:
- 金属有机框架 (MOF) 是具有可调节性质的多孔晶体材料.
- 一氧化碳 (CO) 是一种关键的工业气体,需要高效的分离技术.
研究的目的:
- 为了研究六个M2 ((dobdc) 金属有机框架的CO结合能力.
- 描述CO和金属中心之间的结构和电子相互作用.
- 评估这些MOF在CO分离应用中的潜力.
主要方法:
- 综合和结构性表征六个M2{\ dobdc) MOFs.
- 红外光谱学用于研究CO协调和电子相互作用.
- 用X射线晶体学来确定M-CO键的距离和角度.
- 密度函数理论 (DFT) 计算用于电子结构分析.
- 气体吸附异热量测量以量化CO吸收和吸附热量.
- 理想吸附溶液理论 (IAST) 用于选择性计算.
主要成果:
- 所有六个M2 ((dobdc) 框架都在高容量时表现出可逆CO结合.
- 红外光谱显示了蓝色转移的C-O拉伸频率,表明非经典的金属-CO相互作用.
- 结晶学数据显示了系列中不同的M-CO距离和M-C-O角度.
- DFT计算与实验光谱和结构趋势的相关性很好.
- 在Fe,Co和Ni框架中,CO吸附能力接近每个金属位点的1CO.
- 吸附的异质热量遵循欧文-威廉姆斯顺序,Ni > Co > Fe > Mg > Mn > Zn.
结论:
- M2 ((dobdc) 框架显示出作为固体吸附剂用于CO分离的巨大潜力.
- 这些MOF有可能取代能源密集的冷蒸用于CO净化.
- 选择的金属 (M) 会影响吸附剂的再生能量和气体的纯度.
- 本研究介绍了第一个结晶学特征的Mg和Zn碳化合物以及M = Mn,Fe,Co,Ni的高旋转M(II) 碳物种.
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