A series of amine-based adsorbents were synthesized using siliceous MCM-41 individually impregnated with four different amines（ethylenediamine（EDA）,diethylenetriamine（DETA）,tetraethylenepentamine（TEPA） and pent...A series of amine-based adsorbents were synthesized using siliceous MCM-41 individually impregnated with four different amines（ethylenediamine（EDA）,diethylenetriamine（DETA）,tetraethylenepentamine（TEPA） and pentaethylenehexamine（PEHA）） to study the effect of amine chain length and loading weight on their CO2 adsorption performances in detail.The adsorbents were characterized by FT-IR,elemental analysis,and thermo-gravimetric analysis to confirm their structure properties.Thermo-gravimetric analysis was also used to evaluate the CO2 adsorption performance of adsorbents.Longer chain amine-based materials can achieve higher amine loadings and show better thermal stability.The CO2 adsorption capacities at different temperatures indicate that the CO2 adsorption is thermodynamically controlled over EDAMCM41 and DETA-MCM41,while the adsorption over TEPA-MCM41 and PEHA-MCM41 is under kinetic control at low temperature.The chain length of amines affects the CO2 adsorption performance and the adsorption mechanism significantly.The results also indicate that CO2 adsorption capacity can be enhanced despite of high operation temperatures,if appropriate amines（TEPA and PEHA） are applied.However,adsorbents with short chain amine exhibit higher adsorption and desorption rates due to the collaborative effect of rapid reaction mechanisms of primary amines and less diffusion resistance of shorter chain length amines.展开更多
制备了不同Al含量的Al-MCM-41试样,其中Si/Al比值最小为3,即最高含铝量xAl=0.303.X射线粉末衍射（XPD）分析表明样品具有MCM-41的特征结构,氮气吸附研究表明,样品呈现Ⅳ型吸附等温线,具有孔径分布均一的中孔结构.文中还利用27Al MAS NM...制备了不同Al含量的Al-MCM-41试样,其中Si/Al比值最小为3,即最高含铝量xAl=0.303.X射线粉末衍射（XPD）分析表明样品具有MCM-41的特征结构,氮气吸附研究表明,样品呈现Ⅳ型吸附等温线,具有孔径分布均一的中孔结构.文中还利用27Al MAS NMR研究了试样中Al的化学环境,结果表明,即使在高铝含量的情况下,样品中的铝原子仍以四配位结合在MCM-41的硅骨架上,未能检测出骨架外六配位铝的存在.文中还就Al含量对孔结构的影响以及Al-MCM-41形成机理作了讨论.展开更多
基金supported by the National Natural Science Foundation of China(91434120)the Fundamental Research Funds for the Central Universities(2014ZD06),and the 111 Project(No.B12034)
文摘A series of amine-based adsorbents were synthesized using siliceous MCM-41 individually impregnated with four different amines（ethylenediamine（EDA）,diethylenetriamine（DETA）,tetraethylenepentamine（TEPA） and pentaethylenehexamine（PEHA）） to study the effect of amine chain length and loading weight on their CO2 adsorption performances in detail.The adsorbents were characterized by FT-IR,elemental analysis,and thermo-gravimetric analysis to confirm their structure properties.Thermo-gravimetric analysis was also used to evaluate the CO2 adsorption performance of adsorbents.Longer chain amine-based materials can achieve higher amine loadings and show better thermal stability.The CO2 adsorption capacities at different temperatures indicate that the CO2 adsorption is thermodynamically controlled over EDAMCM41 and DETA-MCM41,while the adsorption over TEPA-MCM41 and PEHA-MCM41 is under kinetic control at low temperature.The chain length of amines affects the CO2 adsorption performance and the adsorption mechanism significantly.The results also indicate that CO2 adsorption capacity can be enhanced despite of high operation temperatures,if appropriate amines（TEPA and PEHA） are applied.However,adsorbents with short chain amine exhibit higher adsorption and desorption rates due to the collaborative effect of rapid reaction mechanisms of primary amines and less diffusion resistance of shorter chain length amines.
文摘制备了不同Al含量的Al-MCM-41试样,其中Si/Al比值最小为3,即最高含铝量xAl=0.303.X射线粉末衍射（XPD）分析表明样品具有MCM-41的特征结构,氮气吸附研究表明,样品呈现Ⅳ型吸附等温线,具有孔径分布均一的中孔结构.文中还利用27Al MAS NMR研究了试样中Al的化学环境,结果表明,即使在高铝含量的情况下,样品中的铝原子仍以四配位结合在MCM-41的硅骨架上,未能检测出骨架外六配位铝的存在.文中还就Al含量对孔结构的影响以及Al-MCM-41形成机理作了讨论.
