Pato-Doldán Breogán, Rosnes Mali H, Dietzel Pascal D C
Department of Chemistry, University of Bergen, P.O. Box 7803, N-5020, Bergen, Norway.
ChemSusChem. 2017 Apr 22;10(8):1710-1719. doi: 10.1002/cssc.201601752. Epub 2017 Mar 16.
The CO adsorption process in the family of porous metal-organic framework materials CPO-27-M (M=Mg, Mn, Co, Ni, Cu, and Zn) was studied by variable-temperature powder synchrotron X-ray diffraction under isobaric conditions. The Rietveld analysis of the data provided a time-lapse view of the adsorption process on CPO-27-M. The results confirm the temperature-dependent order of occupation of the three adsorption sites in the pores of the CPO-27-M materials. In CPO-27-M (M=Mg, Mn, Co, Ni, and Zn), the adsorption sites are occupied in sequential order, primarily because of the high affinity of CO for the open metal sites. CPO-27-Cu deviates from this stepwise mechanism, and the adsorption sites at the metal cation and the second site are occupied in parallel. The temperature dependence of the site occupancy of the individual CO adsorption sites derived from the diffraction data is reflected in the shape of the volumetric sorption isotherms. The fast kinetics and high reversibility observed in these experiments support the suitability of these materials for use in temperature- or pressure-swing processes for carbon capture.
在等压条件下，通过变温粉末同步辐射X射线衍射研究了多孔金属有机骨架材料CPO-27-M（M = Mg、Mn、Co、Ni、Cu和Zn）系列中的CO吸附过程。对数据进行的Rietveld分析提供了CPO-27-M上吸附过程的时间推移视图。结果证实了CPO-27-M材料孔中三个吸附位点的占据顺序与温度有关。在CPO-27-M（M = Mg、Mn、Co、Ni和Zn）中，吸附位点按顺序被占据，主要是因为CO对开放金属位点具有高亲和力。CPO-27-Cu偏离了这种逐步机制，金属阳离子处的吸附位点和第二个位点被并行占据。从衍射数据得出的单个CO吸附位点的占据情况对温度的依赖性反映在体积吸附等温线的形状上。在这些实验中观察到的快速动力学和高可逆性支持了这些材料适用于变温或变压碳捕获过程。
