Micropore Formation of [Zn2(Oxac) (Taz)2]·(H2O)2.5 via CO2 Adsorption

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• 作者：Moondra Zubir ; Atom Hamasaki ; Taku Iiyama ; Akira Ohta ; Hiroshi Ohki ; Sumio Ozeki
• 刊名：Langmuir
• 出版年：2017
• 出版时间：January 24, 2017
• 年：2017
• 卷：33
• 期：3
• 页码：680-684
• 全文大小：396K
• ISSN：1520-5827

文摘

As-synthesized [Zn₂(Oxac) (Taz)₂]·(H₂O)_2.5, referred to as ZOTW_2.5, was prepared from aqueous methanol solutions of Zn₅(CO₃)₂(OH)₆ and two kinds of ligands of 1,2,4-triazole (Taz) and oxalic acid (Oxac) at 453 K for 12 h. The crystal structure was determined by the Rietveld method. As-synthesized ZOTW_2.5 was pretreated at 383 K and 1 mPa for t_pt h, ZOTW_x(t_pth). ZOTW_x(≥3h) showed a type I adsorption isotherm for N₂ at 77 K having a saturation amount (V_s) of 180 mg/g, but that pretreated shortly showed only 1/10 in V_s. CO₂ was adsorbed at 303 K in sigmoid on nonporous ZOTW_x(≤2h) and in Langmuir-type on ZOTW_x(≥3h) to reach the adsorption amount of 120 mg/g at 700 Torr. N₂ adsorption on ZOTW_x(≤2h)deCO₂, degassed after CO₂ adsorption on ZOTW_x(≤2h), was promoted 5-fold from 180 mg/g on ZOTW_x(t_pth) and ZOTW_x(≥3h)deCO₂ up to ca. 1000 mg/g. The interaction of CO₂ and H₂O molecules in micropores may lead to a new route for micropore formation.