摘要
CO_(2)的催化转化是实现碳减排的重要手段。金属有机框架ZIF-8可催化CO_(2)与环氧化合物环加成制备环状碳酸酯。为通过缺陷工程提高ZIF-8的催化活性,将其在200℃、空气气氛热处理7 h。用SEM、TEM、XRD、FT-IR、UV和XPS对材料进行表征。结果表明,热处理消除了部分有机配体2-甲基咪唑,在ZIF-8中产生大量缺陷,使更多的Zn活性位点暴露在表面。以CO_(2)与环氧氯丙烷环加成为模型反应,考察缺陷工程对催化活性的影响,并对反应条件进行优化。结果表明,与ZIF-8相比,缺陷ZIF-8(DZIF-8)的催化活性大幅提高,在100℃、3.0 MPa、DZIF-8用量50 mg、环氧氯丙烷6 mL条件下反应16 h,环氧氯丙烷完全转化。DZIF-8重复使用6次后,环氧氯丙烷转化率下降到89.1%,显示出较高的稳定性。
Catalytic conversion of CO_(2) is an important route to reduce carbon emission.ZIF-8 is a metal organic framework,which can catalyze the cycloaddition of CO_(2) and epoxides to prepare cyclic carbonates.In order to improve the catalytic activity through defect engineering,ZIF-8 is heated at 200℃for 7 h in air atmosphere.The materials are characterized by SEM,TEM,XRD,FT-IR,UV and XPS.The results show that heating eliminates some organic ligands 2-methylimidazole.A large number of defects are generated in ZIF-8 and more Zn active sites are exposed on the surface.The cycloaddition of CO_(2) and epichlorohydrin is used as a model reaction to evaluate the effect of defect engineering on catalytic activity.The reaction conditions are also optimized.The results show that the catalytic activity of the defective ZIF-8(DZIF-8)is much higher than that of ZIF-8.Under the conditions of 100℃,3.0 MPa and 50 mg of DZIF-8,6 mL of epichlorohydrin is converted completely within 16 h.DZIF-8 shows high stability.The conversion of epichlorohydrin decreases only to 89.1%after 6 cycles of the reaction.
作者
王忠华
朱桂生
邵守言
吴杰
Wang Zhonghua;Zhu Guisheng;Shao Shouyan;Wu Jie(Jiangsu Sopo Group Co.,Ltd.,Zhenjiang 212006,Jiangsu,China;Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China)
出处
《工业催化》
2021年第8期39-45,共7页
Industrial Catalysis
