Adsorption of Water Insoluble Porphyrin to Trioctahedral Layered Aluminosilicate and Its Surface Acidity
Adsorption of Water Insoluble Porphyrin to Trioctahedral Layered Aluminosilicate and Its Surface Acidity
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DOI：
10.1246/bcsj.20200066
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发表时间：
2020-07-01
影响因子：
4
通讯作者：
Eguchi, Miharu
中科院分区：
文献类型：
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作者：
Eguchi, Miharu
本研究研究了非离子型水不溶性有机分子（中四苯基卟啉，TPP）在有机溶剂中对三八面体层状铝硅酸盐（皂土，SP）的吸附，以研究SP作为吸附剂对除阳离子或极性分子外的更广泛分子的吸附性能。溶剂对层状硅酸铝表面的亲和力是预测分子吸附性能的重要因素。即选择对硅酸铝亲和力较低的溶剂，使分子能够接近表面，从而促使分子吸附。在这些条件下，由于TPP的碱性和酸性，它被吸附在SP上。SP吸附TPP的酸为Lewis酸。与Bronsted酸相比，较弱的酸强度（H-0，估计为0.8-1.5）似乎更适合吸附剂，因为分子从SP中有效地回收，其分子内电荷分布发生了移位。SP的酸度在本研究中进行了定量讨论，因为与传统用作催化剂的双八面体铝硅酸盐（如蒙脱土）相比，SP的酸度还没有得到彻底的研究。
This study investigated the adsorption of a non-ionic water-insoluble organic molecule (meso-tetraphenylporphyrin, TPP) on a trioctahedral layered aluminosilicate (saponite, SP) in organic solvents in order to investigate properties of SP as an adsorbent for a wider variety of molecules, other than cationic or polar ones. The affinity of solvents for the layered aluminosilicate surface was an important factor for predicting the molecule's adsorption proprieties. Namely, solvents with low affinity for the aluminosilicate should be selected so that molecules can approach the surface, thus prompting adsorption of the molecules. Under these conditions, TPP was adsorbed to SP due to their basicity and acidity. The acid on SP adsorbing TPP was revealed to be Lewis acid. The weaker acid strength (H-0, estimated to be 0.8-1.5) compared with that of Bronsted acids appeared to be more suitable for adsorbents because molecules are recovered efficiently from SP where their intramolecular charge distributions are shifted. The acidity of SP is discussed quantitatively in this study because this has not been done thoroughly in comparison with dioctahedral aluminosilicates such as montmorillonite, which are conventionally used as catalysts.