【摘要】：金屬-有機框架(metal organic frameworks,MOFs)具有長程有序的結(jié)構(gòu)、高度的可設(shè)計性,可用于構(gòu)筑理想的氫鍵網(wǎng)絡(luò),因而在質(zhì)子傳導(dǎo)領(lǐng)域備受關(guān)注。目前,影響MOFs質(zhì)子傳導(dǎo)性能的因素主要有質(zhì)子濃度、質(zhì)子遷移率、質(zhì)子跳躍位點等。受材料結(jié)構(gòu)模型的限制,質(zhì)子傳輸路徑的輪廓對質(zhì)子傳導(dǎo)性能的影響還未被證實。一種理想的解決方案是在同一個MOF中構(gòu)筑不同的質(zhì)子傳輸路徑。MIL-101包含兩種不同尺寸的籠,它們在空間上有序排列,分別形成了兩種輪廓的通道——Z字形和直線型。由于MIL-101的籠擁有大尺寸的可進入的窗口,因此可以通過引入客體分子人為地構(gòu)筑氫鍵通路。Keggin型多金屬氧酸鹽H3PW12O40(HPW)具有獨特的納米尺寸、強的Br?nsted酸性、良好的穩(wěn)定性和豐富的質(zhì)子跳躍位點,是一種理想的選擇。在這里,我們將HPW分別引入到MIL-101的兩種籠內(nèi),獲得了Z字形和直線型兩種不同輪廓的氫鍵網(wǎng)絡(luò)。測試結(jié)果表明,直線型氫鍵網(wǎng)絡(luò)的質(zhì)子傳輸速率是Z字型氫鍵網(wǎng)絡(luò)的兩倍之多,進一步表明直線型路徑相比于Z字形路徑更有利于快速的質(zhì)子傳輸。這為設(shè)計基于MOFs的質(zhì)子導(dǎo)體提供了除載體/質(zhì)子濃度和遷移率以外的新的觀點。此外,我們用柔性的胺分子對擔(dān)載HPW的MIL-101進行后合成修飾,進一步提高其質(zhì)子電導(dǎo)率至1.52×10-2 S cm-1在80℃100%RH下。
[Abstract]:Metal-organic frameworks,MOFs (MOF), with its long-range ordered structure and highly Designability, can be used to construct ideal hydrogen-bonded networks, so it has attracted much attention in the field of proton conduction. At present, proton concentration, proton mobility, proton jump sites and so on are the main factors that affect the proton conduction performance of MOFs. Limited by the material structure model, the influence of the profile of the proton transport path on the proton conduction performance has not been confirmed. One ideal solution is to construct different proton transport paths in the same MOF. Mil-101 consists of two different size cages, arranged in order in space, forming two channels of contour-Z-shaped and straight-line. Since the cage of MIL-101 has a large and accessible window, the hydrogen bond pathway can be constructed artificially by introducing guest molecules. Keggin type polyoxometalate H3PW12O40 (HPW) has unique nano-size and strong Br?nsted acidity. Good stability and rich proton jump sites are an ideal choice. In this paper, we introduce HPW into two kinds of cages of MIL-101, and obtain two kinds of H-bond networks with Z-shape and linear contour. The test results show that the proton transfer rate of the linear hydrogen-bond network is twice as much as that of the Z-shaped hydrogen-bond network, which further indicates that the linear path is more favorable to the rapid proton transport than the Z-shaped path. This provides a new point of view for the design of proton conductors based on MOFs in addition to carrier / proton concentration and mobility. In addition, we modified the MIL-101 loaded with HPW with flexible amine molecules and further improved the proton conductivity of MIL-101 to 1.52 脳 10? s cm-1 at 80 鈩，

本文編號：2456244