硝基功能化MOF中的CO_(2)捕获分离

The CO_(2)capture and separation in nitro-functionalized MOFs

随着全球工业化进程的加速,能源消耗持续增加带来CO_(2)的过度排放,引发了严重的气候与环境问题。在众多应对措施中,以具有独特孔隙特征的MOF材料为代表的物理吸附技术成为该领域的研究热点。基于PtS型MOF材料,设计构建并优化了一系列硝基(-NO_(2))和三嗪修饰的MOF结构,通过巨正则蒙特卡洛(GCMC)理论模拟研究了不同-NO_(2)数量对MOF材料的CO_(2)气体吸附分离性能的影响。结果表明:在298K和1.0bar条件下,引入-NO_(2)后,材料对CO_(2)的捕获量从PtS的1.92mmol/g提升到了PtS-2NO_(2)的2.52mmol/g,增加-NO_(2)数量后PtS-4NO_(2)的CO_(2)吸附量提升到了5.02mmol/g,而同时修饰三嗪结构后CO_(2)吸附量达到5.93mmol/g。计算不同结构的等温吸附热、van der Waals/Coulomb相互作用和选择性等揭示了MOF结构中引入-NO_(2)对其CO_(2)选择性吸附能力的促进作用和机制,对高性能MOF基CO_(2)吸附剂材料的开发具有重要的指导意义。

With the acceleration of global industrialization,the continuous increase in energy consumption has led to excessive CO_(2)emissions,causing severe climate and environmental issues.Among various countermeasures,physical adsorption technology represented by MOF materials with unique pore characteristics has become a research hotspot in this field.Based on PtS-type MOF materials,a series of MOF structures modified with nitro(-NO_(2))and triazine were designed,constructed and optimized.The effect of different amounts of-NO_(2)on the CO_(2)gas adsorption and separation performance of MOF materials was simulated and investigated by grand canonical Monte Carlo(GCMC)theory.The results showed that at 298K and 1.0bar,the introduction of-NO_(2)increased the CO_(2)capture amount from 1.92mmol/g of PtS to 2.52mmgl/g of PtS-2NO_(2),and further augmentation of-NO_(2)groups raised the CO_(2)adsorption capacity to 5.02mmol/g of PtS-4NO_(2),while the CO_(2)adsorption reached 5.93mmol/g after simultaneous modification with triazine structure.Calculation of isosteric heat of adsorption,van der Waals/Coulomb interactions,and selectivity also demonstrated the enhancement of CO_(2)selective adsorption performance due to-NO_(2)functionalization.In addition,the mechanisms by which-NO_(2)facilitated this enhancement were elucidated through van der Waals/Coulomb interactions.This research provides significant guidance for the development of MOF-based CO_(2)adsorbent materials.