Cu-MOFs的生长调控及其催化水解羰基硫的性能（英文）

发布时间：2018-05-25 03:24

本文选题：金属-有机骨架材料 + 羰基硫　；参考：《催化学报》2017年08期

【摘要】：羰基硫(COS)广泛存在于以煤、焦炭、渣油和天然气等为原料生产的化工原料气中,不仅腐蚀管道设备,使下游催化剂发生硫中毒,而且还会造成环境污染.因此,COS脱除具有重要意义.在各种方法中,催化水解COS(COS+H_2O→CO_2+H_2S)由于具有反应条件温和、转化率高和副反应少等优点越来越受重视.其关键在于发展高效的催化剂.近年来,金属-有机骨架材料(metal-organic frameworks,MOFs)由于其独特的物理化学性质引起人们广泛关注.与传统材料相比,MOFs不仅拥有超高的比表面积和规则的孔道结构,而且其结构具有可设计性强和易调变等特点,是一类非常有潜力的多相催化剂.然而,目前MOFs在催化水解COS方面的研究应用未见报道.此外,MOFs的合成方法主要有水/溶剂热法、扩散法和微波辅助加热法等.近年来新发展的电化学法具有合成效率高、操作方便和环境友好等优点,在材料合成中显示出巨大的优越性,但利用电化学法合成MOFs相关研究还较少.本文采用快速温和的电化学方法制备了典型的Cu-MOFs(HKUST-1).该方法可以有效缩短反应时间,通过调节反应电压(15 30 V),在室温下电解3 h,可得到一系列HKUST-1样品.根据合成中设置的电压值,样品分别命名为HKUST-1-E15,HKUST-1-E20,HKUST-1-E25和HKUST-1-E30.XRD表征结果显示,不同电压下合成样品的XRD谱图与通过晶体数据拟合的HKUST-1图出峰位置基本一致.SEM结果表明,合成电压对样品形貌的影响很大.HKUST-1-E15主要呈长棒状结构,长约为15μm.随着电压的增大,HKUST-1-E20的形貌逐渐转变为较短的四棱柱体.当电压为25 V时,所得HKUST-1-E25呈八面体状.进一步提高合成电压,HKUST-1-E30颗粒变小,没有特殊形貌,并出现明显的团聚.COS水解测试结果显示,不同电压下合成样品的活性差异大,这主要是由于样品的形貌及比表面积差异引起的.其中,HKUST-1-E25样品的活性较好.在150°C下,该样品对COS的转化率接近100%,比水热法合成的HKUST-1-Hy的活性更高.在此基础上,进一步对活性测试过程的条件进行优化,发现当原料气流速为30 mL/min,水温为40°C时,催化剂的COS水解性能最优.此外,样品的活性稳定性测试结果显示,相比传统的氧化铜材料,HKUST-1是一类较稳定的COS水解催化剂.
[Abstract]:Carbonyl sulfur (COS) is widely used in chemical raw gas produced from coal, coke, residuum and natural gas. It not only corrodes pipeline equipment and causes sulfur poisoning in downstream catalyst, but also causes environmental pollution. Therefore, the removal of COS is of great significance. Among the various methods, the catalytic hydrolysis of COS(COS H _ 2O CO_2 H _ 2s has attracted more and more attention due to its mild reaction conditions, high conversion rate and less side reactions. The key is to develop efficient catalysts. In recent years, metal-organic framework materials (metal-organic frameworks) have attracted wide attention due to their unique physical and chemical properties. Compared with traditional materials, MOFs not only have high specific surface area and regular pore structure, but also have the characteristics of high designability and easy to adjust, so they are a kind of potential heterogeneous catalysts. However, the application of MOFs in catalytic hydrolysis of COS has not been reported. In addition, the synthesis methods of MOFs mainly include hydrothermal method, diffusion method and microwave-assisted heating method. In recent years the newly developed electrochemical method has many advantages such as high synthesis efficiency convenient operation and environmental friendliness. It has shown great advantages in the synthesis of materials but there is little research on the synthesis of MOFs by electrochemical method. In this paper, the typical Cu-MOFsN HKUST-1 is prepared by a rapid and mild electrochemical method. This method can effectively shorten the reaction time. A series of HKUST-1 samples can be obtained by electrolysis at room temperature for 3 h by adjusting the voltage of the reaction. According to the voltage values set in the synthesis, the samples were named HKUST-1-E15 (HKUST-1-E20) HKUST-1-E25 and HKUST-1-E30.XRD characterization results showed that the XRD spectra of the synthesized samples at different voltages were basically consistent with the peak locations of the HKUST-1 diagrams fitted by crystal data. The synthesis voltage has great influence on the morphology of the sample. HKUST-1-E15 is a long rod structure with a length of about 15 渭 m. With the increase of voltage, the morphology of HKUST-1-E20 is gradually changed to a shorter tetrahedral cylinder. When the voltage is 25 V, the HKUST-1-E25 is octahedral. Further increasing the synthesis voltage, the HKUST-1-E30 particles become smaller and have no special morphology, and the results of hydrolytic test of obvious agglomeration. COS show that the activity of the synthesized samples varies greatly at different voltages. This is mainly due to the difference in the morphology and specific surface area of the sample. Among them, the activity of HKUST-1-E 25 was better. At 150 掳C, the conversion of COS was close to 100%, which was higher than that of HKUST-1-Hy synthesized by hydrothermal method. On this basis, the conditions of the activity test process were further optimized. It was found that the COS hydrolysis performance of the catalyst was optimal when the feed flow rate was 30 mL / min and the water temperature was 40 掳C. In addition, the results of activity stability test showed that HKUST-1 was a more stable COS hydrolysis catalyst than the traditional copper oxide material.
【作者单位】：福州大学化肥催化剂国家工程研究中心;
【基金】：supported by the National Natural Science Foundation of China (21603034,21576051) the National High Technology Research and Development Program of China (863 Program,2015AA03A402)~~
【分类号】：O643.36

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