Study On The Selective Adsorption Of Co₂ Based On An N-containing Metal-organic Framework

Metal-organic frameworks are constructed from the self-assembly of bridging organic ligands and metal ions or clusters. Functional materials can be obtained by a judicious choice of these basic components(molecular building blocks) prior to their synthesis. More and more attentions have been attracted on(MOFs), owing to their many potential applications, such as ion exchange, gas storage, gas separation, magnetism, photology and catalysis. Due to its their tunable composition, structure, pore size, and volume, easy functionalization, flexible network and/or accessible metal sites, MOFs possess many advantages for the gas adsorption and separation compared to other carriers such as inorganic porous solids(zeolites or mesoporous silica) or organic polymers.A new MOF(NENU-520) has been successfully harvested by means of solvothermal reaction, with the accessible free nitrogen atoms directing toward the inner surface. NENU-520 has good air-stability even in the existence of moisture. Activated NENU-520 a exhibits strong adsorption capacity towards H2 and CO2 with high adsorption enthalpy of 10.7 k J mol-1 and 33 k J mol-1, respectively. Moreover, NENU-520 a shows high CO2/CH4 and CO2/N2 selectivities calculated via combination of the Ideal Adsorbed Solution Theory and breakthrough simulations for a realistic consideration. In particular, the selectivity of CO2 over N2 at 298 K of NENU-520 a is amongst the highest values for CO2 selective separation. Consequently, NENU-520 a has significant potential for use as adsorbent in CO2-capture for natural gas sweetening and post-combustion power plants, combines the higher uptake and higher selectivity toward CO2. The narrow but suitable channel as well as the effective accessible nitrogen donors directing toward the inner surface is demonstrated to be the predominant factor for the high uptake capacity and unprecedented selectivity. Additionally, NENU-520 a displays highly selective, sensitive and recyclable properties in detection of nitrobenzene as a fluorescent sensor because of its quenching effect in nitrobenzene.[Zn2L2]·2DMF(NENU-520)(H2L, 4-(1H-tetrazole-5-yl)biphenyl-4-carboxylic acid)We using flexible H2L(4-(1H-tetrazole-5-yl)biphenyl-4-carboxylic acid) and zinc nitrate(or cadmium nitrate), via controlling synthesis condition obtain two metal-organic frameworks. The Cd-base framework(1) exhibits a 3D(4,4)-connected network. While the Zn-base framework(2) is a 2D wave-like sheet, the overall framework of 2 can be regarded as a(3,3)-connected net. Both 1 and 2 possess extraordinarily high water stability and chemical stability. Furthermore, they have potential applications in the field of anion detection.[Cd L]·H2O(1)[Zn L]·H2O(2)(H2L, 4-(1H-tetrazole-5-yl)biphenyl-4-carboxylic acid)...