Synthesis of ZIF-8 and ZIF-67 by Steam-Assisted Conversion and an Investigation of Their Tribological Behaviors
Synthesis of ZIF-8 and ZIF-67 by Steam-Assisted Conversion and an Investigation of Their Tribological Behaviors
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DOI：
10.1002/anie.201004937
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发表时间：
2011-01-01
影响因子：
16.6
通讯作者：
Dong, Jinxiang
中科院分区：
文献类型：
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作者：
Shi, Qi;Chen, Zhaofeng;Dong, Jinxiang
分子筛咪唑骨架(ZIF)是多孔金属有机骨架(MOF)的一个新的子类，通常具有膨胀的分子筛拓扑结构。同时，它们还具有传统沸石的高化学和热稳定性。[4]由于这些组合和理想的特性，ZIF-8(锌(Mim)2，mim=2-甲基咪唑)和ZIF-67(Co(Mim)2)是最具代表性的具有分子筛超氧化物歧化结构的ZIF-8(锌(Mim)2，mim=2-甲基咪唑)。扩展的草皮框架展示了耐人寻味的特征：一个大的草皮笼(11.6)可以通过一个狭窄的六环孔(3.4)到达。此外，ZIF-8具有高热稳定性(氮气中5508C)和大比表面积(BET：1630m2g±1)。[4]这些特性使ZIF-8成为最成熟的ZIF材料，并得到了各种令人印象深刻的应用。[9，11，13-15]热稳定性和化学稳定性的ZIF-8和ZIF-67通常是用DMF作为有机溶剂合成的，最终填充了孔隙空间。[4]然而，客体分子DMF实际上比草皮笼的孔径大，不能直接释放。它们的广泛应用要求ZIF-8和ZIF-67样品的合成和活化是简单和环保的。因此，无溶剂(熔融)合成(可能是因为MIM：MP 1448C的低熔点)或水热合成，对于开发有效和环境友好的ZIF-8和ZIF-67路线具有巨大的潜力。实际上，在没有有机溶剂DMF的情况下，加热低于MIM熔点的锌-(OAc)2和MIM的混合物就会形成共晶混合物(辅助信息，图S1)。然后将共晶混合物在1208C或1508C下保持24小时。然而，对未洗涤产物的粉末X射线衍射(PXRD)分析表明，这种无溶剂(熔融)合成并没有
Zeolitic imidazolate frameworks (ZIFs) are a new subclass of porous metal–organic frameworks (MOFs) which frequently have expanded zeolite topologies.[1–8] Most interestingly, some guest-free ZIFs have the large surface area and pore volume of classical MOFs; at the same time, they also have the high chemical and thermal stability of conventional zeolites.[4] Because of these combined and desirable features, ZIFs show great potential for many applications, especially for gas storage and separations.[5, 9–12] ZIF-8 (Zn (mim) 2, mim= 2-methylimidazolate) and ZIF-67 (Co (mim) 2) are the most representative ZIF materials with a zeolite sod topology. The expanded sod framework exhibits intriguing features: a large sod cage (11.6) is accessible through a narrow six-ring pore (3.4). Moreover, ZIF-8 has a high thermal stability (5508C in N2) and large surface area (BET: 1630 m2 gÀ1).[4] These features have made ZIF-8 the most established ZIF material and it has found a variety of impressive applications.[9, 11, 13–15]Thermally and chemically stable ZIF-8 and ZIF-67 have generally been synthesized by using DMF as an organic solvent that ultimately fills the pore space.[4] However, the guest molecule DMF is actually larger than the aperture of the sod cage, and could not be directly released. Their extensive applications require that the synthesis and activation of ZIF-8 and ZIF-67 samples are facile and environmentally friendly. Therefore, solvent-free (melting) synthesis (possible because of the low melting point of mim: mp 1448C) or hydrothermal synthesis, have significant potential for the development of effective and environmentally benign routes to ZIF-8 and ZIF-67. Actually, in the absence of the organic solvent DMF, a eutectic mixture is formed upon heating a mixture of Zn-(OAc) 2 and mim below the melting point of mim (Supporting Information, Figure S1). The eutectic mixture was then kept for 24 h either at 1208C or 1508C. However, the powder X-ray diffraction (PXRD) analysis of the unwashed products showed that this solvent-free (melting) synthesis had not