The Preparation And Research Of Porous Aromatic Frameworks With Superior Adsorption Properties

In the recent decade, porous materials, especially porous aromatic frameworks(PAFs), become a series of high-profile emerging materials because of their excellentproperties. Their attractive advantages, including low skeleton density, rigid structuralnetworks and large specific surface areas, provide PAFs with possibilities in the areaof gas adsorption and storage, heterogeneous catalysis, sensors, and electricity. Thisthesis is dedicated to synthesize PAFs in a low-cost and effective method and exploretheir properties in terms of gas adsorption.First, the classic monomers of PAFs are selected to construct PAFs with cheapLewis acid catalyst by Scholl reaction. Four new PAF materials, PAF-41, PAF-42,PAF-43and PAF-44, with moderate Brunauer-Emmett-Teller (BET) surface areas(515-1119m2g-1) are obtained. Among the obtained PAF materials, PAF-41exhibitsthe best CH4and CO2sorption capacity, and PAF-43demonstrate its comparably highisosteric heat of adsorptions.Then, a series of low-cost multi-benzene compounds are selected as buildingunits, and those phenyl rings could couple together to form polymeric skeletons withScholl Reaction. Although the BET surface areas of the resulting PAFs are moderate,ranging from777to972m2g-1, they unexpectedly exhibit superior gas sorptioncapacities. At1.0bar and77K, the H2uptake of PAF-48reaches215cm3g-1. Besides,PAF-49shows an excellent performance in carbon dioxide and methane sorption, withthe values of104cm3g-1and35cm3g-1, respectively.The preparation of materials mentioned above provide new synthesis methods forPAFs. The new strategy not only decreases the manufacturing costs of PAFs, but alsopromotes their performance in gas adsorption. With those excellent adsorptionproperties towards energy gases and greenhouse gases, these PAF materials could beconsidered as potential candidates for energetic gas adsorbents and of great value forfurther development.