氨气改性的NH_3@MIL-53(Cr)吸附CO_2和CH_4的性能  

CO_2 and CH_4 adsorption performance of modified MIL-53(Cr)via ammonia vapor

作　　者：杨琰[1] 王莎[1] 张志娟[2] 夏启斌[1] 李忠[1] 

机构地区：[1]华南理工大学化学与化工学院,广东广州510640 [2]暨南大学大气环境安全与污染控制研究所,广东广州510632

出　　处：《化工学报》2014年第5期1759-1763,共5页CIESC Journal

基　　金：国家重点基础研究发展计划项目(2013CB733506);国家自然科学基金项目(21176085)~~

摘　　要：采取水热法成功合成MIL-53(Cr)晶体,分别应用0.1、1、3 mol·L?1的氨气对MIL-53(Cr)进行改性,制得系列的NH3@MIL-53(Cr)-1#,NH3@MIL-53(Cr)-2#,NH3@MIL-53(Cr)-3#。实验结果表明:与原始的MIL-53(Cr)晶体相比,尽管制得NH3@MIL-53(Cr)系列材料的比表面积依次减少,但其单位比表面积的CO2吸附容量大小依次为:NH3@MIL-53(Cr)-3#>NH3@MIL-53(Cr)-2#>NH3@MIL-53(Cr)-1#。表明氨气改性会使得材料表面的碱性增强,从而增强了其对酸性气体CO2的吸附。此外,改性后的NH3@MIL-53(Cr)对水蒸气的吸附量明显减少,表明其憎水性能得到改善。较高浓度氨气改性会导致材料的比表面积大幅下降,会引起单位质量吸附剂的吸附容量下降。用1 mol·L?1浓度的氨气改性得到的NH3@MIL-53(Cr)-2#,不仅对CO2的吸附容量最大,而且对CH4的吸附容量明显下降,这将有助于进一步提高改性材料NH3@MIL-53(Cr)-2#对CO2/CH4的吸附选择性。MIL-53（Cr）crystals were synthesized by the hydrothermal synthesis method, and then modified by ammonia vapor of different concentrations to obtain the modified materials NH3@MIL-53（Cr）. The CO2 and water vapor isotherms on the NH3@MIL-53（Cr）were determined by means of the gravity method. Although the specific surface area of the modified materials NH3@MIL-53（Cr）became smaller compared to original MIL-53（Cr）, their CO2 adsorption capacities per unit surface area of adsorbent became significantly higher, following the order： NH3@MIL-53（Cr）-3#〉NH3@MIL-53（Cr）-2#〉NH3@MIL-53（Cr）-1#. In addition, Isotherms of water vapor on the modified samples NH3@MIL-53（Cr） were lower than those on the MIL-53（Cr）, suggesting significant improvement of hydrophobicity of the modified samples. The CO2 adsorption capacity of the NH3@MIL-53（Cr）-2# modified by using ammonia vapor of 1 mol＆#183;L-1 was the highest among the modified samples. More interestingly, the CO2 adsorption performance of the modified sample NH3@MIL-53 （Cr）-2# was significantly improved, while its CH4 adsorption performance was weakened, which would be helpful to enhance＆amp;nbsp;its selectivity for CO2/CH4 adsorption.

关 键 词：MIL-53(Cr) 二氧化碳 甲烷 水蒸气 吸附 氨气 

分 类 号：TQ013[化学工程]