Adsorptive Separation of Light Hydrocarbons and Catalysis of CO2 Cycloaddition over Novel MOFs Or POP Materials

Author:Wang Xun

Supervisor:li zhong


Degree Year:2019





Efficient separation of light hydrocarbons and efficient conversion of CO2 are greatly challenging.This work was mainly focused on the design and synthesis of novel MOFs or POP materials for the efficient separation performances of light hydrocarbons and CO2 cycloaddition reaction.It was involved with the study of the synthesis of several MOFs and POP materials for efficient separation of light hydrocarbons and the preparation of high-metal-density MMPF materials for the high-efficient catalysis of the cycloaddition reaction of CO2 with aziridines,which belongs to the interdisciplinary fields of chemical engineering,catalytic chemistry and material engineering.It is of great significance for the scientific research and practical applications.A series of Ni(BDC)1-x(TMBDC)x(DABCO)0.5(x=0,0.2,0.45,0.71,1)were synethesized and their separation performance toward C2H6/C2H4 binary mixture was examined.Ni(BDC)(DABCO)0.5 was selected as a prototype host material and the TMBDC ligand was introduced into the framework through a mixed-ligand strategy,affording a series of Ni(BDC)1-x(TMBDC)x(DABCO)0.5(x=0,0.2,0.45,0.71,1).The highest C2H6 capacity of5.45 mmol/g and C2H4 capacity of 5.02 mmol/g were achieved on Ni(TMBDC)(DABCO)0.5,as well as C2H6/C2H4 selectivity of 1.945.The separation performance of C1/C2/C3 over an ultramicroporous material Ni(TMBDC)(DABCO)0.5 was investigated.Its adsorption capacity reached 2.93 mmol/g for C2H6 at 10 kPa and 3.37 mmol/g for C3H8 at 5 kPa.Its IAST selectivity for C2/C1 and C3/C1were 29 and 274,respectively,which were the higher than the most of the reported data.The molecular simulation revealed the C2H6 and C3H8 were preferentially adsorbed around the methyl groups and methylene groups,demonstrating the presence of large amount of methyl groups and methylene groups in the channels enhanced the adsorption and selectivity of C2H6and C3H8 on Ni(TMBDC)(DABCO)0.5.A novel strategy for room temperature synthesis of MIL-100(Fe)was proposed.RT-MIL-100(Fe)was successfully prepared at room temperature by using BQ as an accelerant and iron powder as metal source.The mechanism of oxidizing radicals promoting room temperature synthesis of MIL-100(Fe)was subsequently proposed.In addition,the C1/C2/C3 adsorption of the as-synthesized RT-MIL-100(Fe)was investigated.At 298 K and 1 bar,the adsorption capacity of C2H6 and C3H8 reached 2.22 mmol/g and 6.77 mmol/g on RT-MIL-100(Fe),respectively.Fixed bed experiments confirmed that completely C1/C2/C3 ternary mixture was completely separated through the fixed-bed of RT-MIL-100(Fe).A porous organic polymer,CPOP was successfully synthesized through“Click reaction”for the CH4/C2H6/C3H8 separation.The CPOP showed high BET surface area of 1038 m2/g and excellent stability under acid/basic condition.Breakthrough experiment demonstrated complete separation of C1/C2/C3 mixture through the fixed-bed of CPOP with great recycliability.The molecular simulation showed that the CH4,C2H6 and C3H8 molecules were preferentially adsorbed around the N atoms of the triazine ring,forming weak interaction with the N atoms.A novel metal-metalloporphyrin framework,MMPF-10 was synthesized and its catalytic performance in cycloaddition reactions between aziridines and CO2 was explored.MMPF-10possessed an fmj topology with high density of Cu sites that oriented toward the channel.The MMPF-10 was used as a heterogeneous catalyst for CO2 cycloaddition with aziridines and>99%yield of the 3-methyl-5-phenly-2-oxazolidinone was obtained at 100°C,2 MPa.