UiO−66−NH2是典型Zr基金属有机框架(Zr-MOFs),在CO2吸附领域应用前景广阔,是与聚乙烯基胺(PVAm)结合制备混合基质膜(MMMs)的较好填料。但UiO−66−NH2合成反应规模化效应明显,难放大到十克级以上。通过调节水–乙酸的比例,合成了一系列UiO−66−NH2,并通过扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、比表面积测试与孔隙率分析(BET)对样品进行表征。通过分析表征结果,提出一种水–乙酸促进Zr-MOFs二级结构(SBU)形成的机理,以此为指导成功实现UiO−66−NH2颗粒的百克级规模化合成。此外,将该材料与聚乙烯基胺(PVAm)结合制备了UiO−66−NH2/PVAm混合基质膜,用模拟烟道气(CO2、N2体积分数分别为15%、85%)进行分离性能测试,相较纯PVAm膜,UiO−66−NH2/PVAm混合基质膜分离性能提高,CO2渗透率达1937GPU,CO2/N2分离因子达85。根据成本估算结果,用混合基质膜可有效减少碳捕集成本,在实际燃煤烟道气碳捕集中有应用前景。

UiO−66−NH2 is a typical Zr−based metal-organic frameworks (Zr−MOFs) with considerable application prospect in CO2adsorption. It is a good filler combined with polyvinylamine (PVAm) to prepare mixed-matrix membranes (MMMs). However,the scalingeffect of UiO−66−NH2 preparation is too obvious to scale it up to more than ten-gram-scale. A series of UiO−66−NH2 was synthesized bychanging the ratio of water-acetic acid. Scanning Electron Microscope (SEM),X−ray Diffraction (XRD),Fourier Transform Infrared (FT-IR) and BET test were used to characterize the samples. Through the analysis of characterization results,a mechanism for water-acetic acidpromotion of Zr−MOFs secondary-building-unit (SBU) formation was proposed,which has guided the hundred-gram-scale synthesis ofUiO−66−NH2 particles. Furthermore, these particles were combined with polyvinylamine (PVAm) to prepare UiO−66−NH2/PVAmMMMs, whose separation performance were tested using simulated flus gas (volume fractions of CO2 and N2 are 15% and 85%,separately). Compared with PVAm membranes,the separation performance of MMMs increases. The CO2 permeance reaches 1 937 GPUand the CO2/N2 separation factor reaches 85. The result of the cost estimation shows that the use of MMMs can effectively reduce the cost of carbon capture and it also has application prospects in flus gas carbon capture.

0 引言

1 试验

   1.1 药品与试剂

   1.2 UiO−66−NH2制备

   1.3 刮膜液及混合基质膜制备

   1.4 膜性能测试

2 结果与讨论

   2.1 XRD分析

   2.2 扫描电子显微镜(SEM)分析

   2.3 傅里叶变换红外光谱(FT-IR)分析

   2.4 水–乙酸协同调控机理及UiO−66−NH2规模化合成

   2.5 规模化样品比表面积测试(BET)分析

   2.6 UiO−66−NH2颗粒用于PVAm的膜分离性能与分离成本估算

3 结论