Ruthenium Metal-Organic Frameworks with Different Defect Types: Influence on Porosity, Sorption, and Catalytic Properties

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• 作者：Wenhua Zhang ; Max Kauer ; Dr. Olesia Halbherr ; Konstantin Epp ; Penghu Guo ; Miguel I. Gonzalez ; Dianne J. Xiao ; Dr. Christian Wiktor ; Dr. Francesc X. LIabré ; s i Xamena ; Prof. Dr. Christof Wö ; ll ; Dr. Yuemin Wang ; Prof. Dr. Martin Muhler and Prof. Dr. Roland A. Fischer
• 刊名：Chemistry - A European Journal
• 出版年：2016
• 出版时间：September 26, 2016
• 年：2016
• 卷：22
• 期：40
• 页码：14297-14307
• 全文大小：2484K
• ISSN：1521-3765

文摘

By employing the mixed-component, solid-solution approach, various functionalized ditopic isophthalate (ip) defect-generating linkers denoted 5-X-ipH₂, where X=OH (1), H (2), NH₂ (3), Br (4), were introduced into the mixed-valent ruthenium analogue of [Cu₃(btc)₂]_n (HKUST-1, btc=benzene-1,3,5-tricarboxylate) to yield Ru-DEMOFs (defect-engineered metal–organic frameworks) of the general empirical formula [Ru₃(btc)_2−x(5-X-ip)_xY_y]_n. Framework incorporation of 5-X-ip was confirmed by powder XRD, FTIR spectroscopy, ultrahigh-vacuum IR spectroscopy, thermogravimetric analysis, ¹H NMR spectroscopy, N₂ sorption, and X-ray absorption near edge structure. Interestingly, Ru-DEMOF 1 c with 32 % framework incorporation of 5-OH-ip shows the highest BET surface area (≈1300 m² g⁻¹, N₂ adsorption, 77 K) among all materials (including the parent framework [Ru₃(btc)₂Y_y]_n). The characterization data are consistent with two kinds of structural defects induced by framework incorporation of 5-X-ip: modified paddlewheel nodes featuring reduced ruthenium sites (Ru^δ+, 0<δ<2, type A) and missing nodes leading to enhanced porosity (type B). Their relative abundances depend on the choice of the functional group X in the defect linkers. Defects A and B also appeared to play a key role in sorption of small molecules (i.e., CO₂, CO, H₂) and the catalytic properties of the materials (i.e., ethylene dimerization and the Paal–Knorr reaction).