Wu Szu-Chen, Chang Po-Hsueh, Lin Chieh-Yen, Peng Cheng-Hsiung
Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu 300, Taiwan.
Department of Chemical and Materials Engineering, Ming Hsin University of Science and Technology, 1 Xinxing Road, Hsin-Feng Hsinchu 304, Taiwan.
Materials (Basel). 2020 May 12;13(10):2220. doi: 10.3390/ma13102220.
In this study, Ca-based multi-metals metal-organic framework (CaMgAl-MOF) has been designed as precursor material for carbon dioxide (CO) capture to enhance the CO capture capacity and stability during multiple carbonation-calcination cycles. The CaMgAl-MOFs were constructed from self-assembly of metal ions and organic ligands through hydrothermal process to make metal ions uniformly distributed through the whole structure. Upon heat treatment at 600 °C, the Ca-based multi-metals CaMgAl-MOF would gradually transform to CaO and MgO nanoparticles along with the amorphous aluminum oxide distributed in the CaO matrix. XRD, Fourier transform infrared (FTIR), and SEM were used to identify the structure and characterize the morphology. The CO capture capacity and multiple carbonation-calcination cyclic tests of calcined Ca-based metal-organic framework (MOF) (attached with O and indicated as Ca-MOF-O) were performed by thermal gravimetric analysis (TGA). The single metal component calcined Ca-MOF sorbent have the highest CO capture capacity up to 72 wt.%, but a lower stability of 61% due to severe particle aggregation. In contrast, a higher Ca-rich MOF oxide sorbent with tailoring the Mg/Al ratios, CaMgAl-MOF-O, showed the best performance, not only having the high stability of ~97%, but also maintaining the highest capacity of 71 wt.%. The concept of using Ca-based MOF materials combined with mixed-metal ions for CO capture showed a potential route for achieving efficient multiple carbonation-calcination CO cycles.
在本研究中，钙基金属有机框架（CaMgAl-MOF）被设计为用于二氧化碳（CO）捕获的前驱体材料，以提高多次碳酸化-煅烧循环过程中的CO捕获能力和稳定性。CaMgAl-MOF通过金属离子和有机配体在水热过程中自组装构建而成，使金属离子均匀分布于整个结构中。在600℃进行热处理时，钙基金属CaMgAl-MOF会逐渐转变为CaO和MgO纳米颗粒，同时有无定形氧化铝分布在CaO基体中。使用X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和扫描电子显微镜（SEM）来确定结构并表征形态。通过热重分析（TGA）对煅烧后的钙基金属有机框架（MOF）（附着有O并表示为Ca-MOF-O）进行CO捕获能力和多次碳酸化-煅烧循环测试。单一金属组分煅烧后的Ca-MOF吸附剂具有高达72 wt.%的最高CO捕获能力，但由于严重的颗粒团聚，稳定性较低，为61%。相比之下，通过调整Mg/Al比例制备的富钙MOF氧化物吸附剂CaMgAl-MOF-O表现出最佳性能，不仅具有约97%的高稳定性，还保持了71 wt.%的最高捕获能力。使用钙基金属有机框架材料结合混合金属离子进行CO捕获的概念为实现高效的多次碳酸化-煅烧CO循环展示了一条潜在途径。
