摘要
采用溶剂热法制备的生物金属有机框架ZnBTCA,在CO2的吸附过程中表现出有趣的主客体化学现象,通过计算发现随着CO2吸附量的增加,吸附焓逐渐增大。采用4种模型分别对其进行拟合,并通过理想吸附溶液理论模拟预测ZnBTCA对二元混合气体的选择性,试图找到ZnBTCA反常吸附行为的合理解释:ZnBTCA带有氨基和N-活性位点,且孔道内含有大量的客体离子。虽然ZnBTCA孔径较大,但由于其本身的阴离子框架,孔道中的(CH3)2NH2+抗衡离子并未完全去除而降低了可接触的微孔体积,在吸附过程中存在分子筛效应,在二元混合气体中对CO2具有很高的吸附选择性。
A biological metal-organic framework (BioMOF) ZnBTCA was prepared by the solvent-thermal method, which showed interesting host-guest chemistry in CO2 gas adsorption process. It was found that the adsorption enthalpy of CO2 increased with the increase of adsorption capacity. Using four models to fit the adsorption isotherm of CO2, we modeled and predicted the binary mixture selectivity by the ideal adsorbed solution theory (IAST), and tried to find a reasonable explanation for the abnormal adsorption behavior of ZnBTCA. ZnBTCA has high adsorption selectivity for CO2 in CO2/N2 and CO2/CH4 binary systems due to the molecular sieve effect. This is attributed to the fact that ZnBTCA has NH2, N-active site, and a large number of guest cations in the pores. The counterbalancing (CH3)2NH2+ could not be evacuated through thermal activation, and the accessible micropore volume was reduced as a result.
作者
才红
吴光伟
赖佳丽
陈锦萍
陈燕飞
李丹
CAI Hong;WU Guang-Wei;LAI Jia-Li;CHEN Jin-Ping;CHEN Yan-Fei;LI Dan(School of Chemistry and Environmental Engineering, Hanshan Normal University, Chaozhou, Guangdong 521041, China;College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China)
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2019年第11期2083-2088,共6页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金重点项目(No.21731002)
国家自然科学基金青年项目(No.21701038)资助
关键词
金属有机框架
主客体化学
气体吸附
分子筛效应
metal-organic framework
host-guest chemistry
gas absorption
molecular sieve effect
