Microwave synthesis of a nanoporous hybrid material, chromium trimesate

摘要: Recently, the domain of nanoporous materials has been enlarged very much to development porous hybrid designated as metal-organic frameworks (MOF), coordination polymers or organic-inorganic hybrids which are most recently highlighted class consisting metal ions linked together by organic bridging ligands in framework. The attraction combining properties from both inorganic and components led a quest research toward new with potential applications including gas storage, catalysis, separation, molecular recognition. Very recently, Ferey co-workers have reported novel material, chromium trimesate (designated MIL-100), hierarchical pore system (micro: 5-9 A; mesoporous: 25-30 A) high Langmuir surface area. Syntheses carried out mainly hydrothermal solvothermal synthesis generally period several days. Microwave techniques attracted growing attention for rapid requiring days prepare under conditions. Potential advantages this technique include phase selectivity, narrow particle size distribution facile morphology control besides fast crystallization. However, microwave not applied yet even though syntheses only molecules but also often studied. In communication, we report first successful result on an material. (MIL-100) was synthesized aqueous media similar previous method except using irradiation heating source. molar composition reactant mixture 1.0 Cr: 0.67 H3BTC (benzene tricarboxylic acid): 2.0 HF: 290 H2O. loaded Teflon autoclave, sealed placed oven (Mars-5, CEM). autoclave heated reaction temperature 220 C kept predetermined time. structure crystallinity samples were determined X-ray powder diffraction. TGA pattern obtained thermal analyzer air flow. sorption experiments volumetrically. Figure 1 shows XRD patterns as-synthesized varying crystallization time at irradiation. well consistent MIL-100 4 conventional heating. contained unreacted metallic species until 2 h crystal yield based is 44%, comparable 45% profile reveals stability title compound up 270 C. results. nitrogen adsorption-desorption isotherm (Data shown), representing permanent porosity similarity methods. For multiplayer coverage N2, estimate apparent BET area volume be 1700 m/g 0.97 mL/g, respectively. From H2 adsorption (Figure 3), capacity hydrogen –196 atm estimated about 150 mL/g (STP), results adsorbed various MOFs materials. re-adsorption after desorption pre-adsorbed same fresh sample, that there no chemisorption site