Preparation of bromine modified metal-organic frameworks for element mercury adsorption

doi:10.11949/j.issn.0438-1157.20151730

Abstract

Abstract:

Bromine modified metal organic framework (MOF) was synthesized by solvothermal method for element mercury (Hg⁰) adsorption. The crystal structure, chemical and texture properties of the modified MOF were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and N₂ adsorption. Covalent bromine was detected on the surface of the modified MOF and the modification process resulted in a lower specific surface area and total pore volume than those of unmodified MOF. Hg⁰ removal efficiencies increased with temperature for both modified MOF and un-modified MOF sorbent. In the dynamic adsorption experiments, which were conducted trying to mimic the flue gas condition, the bromine modified MOF showed a high Hg⁰ removal efficiency of above 95% for 10 h at 240℃, while the efficiency dropped to 75% within 5 h for both unmodified MOF and traditional active carbon sorbent.

Key words: metal-organic frameworks support, bromine modification, absorption, elemental mercury, flue gas

摘要：

采用溶剂热法制备了溴改性的金属有机骨架(metal organic framework,MOF),通过模拟烟气动态吸附方法对材料单质汞(Hg⁰)吸附性能进行研究。利用X射线衍射(XRD)、X射线光电子能谱(XPS)、综合吸附仪对晶体结构、形貌和组分进行表征。结果表明改性后晶体结构不变,比表面积、孔容下降,溴以共价键固定在材料中。改性前和改性后材料对Hg⁰的吸附效率都有随温度升高而增加趋势。模拟烟气反应床吸附实验证明240℃条件下,溴改性MOF10h内吸附效率高于95%,同等实验条件下,非改性MOF以及传统活性炭吸附剂吸附汞5h后效率低于75%。

关键词: 金属有机骨架载体, 溴改性, 吸附, 单质汞, 烟道气

CLC Number:

X511

ZHANG Xiao, SHEN Boxiong, CHI Guilong, ZHU Shaowen, WANG Zeyi . Preparation of bromine modified metal-organic frameworks for element mercury adsorption[J]. CIESC Journal, 2016, 67(6): 2380-2385.

张笑, 沈伯雄, 池桂龙, 朱少文, 王泽怿. 溴改性金属有机骨架的合成及其对单质汞吸附[J]. 化工学报, 2016, 67(6): 2380-2385.

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