Copper and copper-zinc imidazolate frameworks were successfully synthesized using improved mild acid catalyzed method. Imidazolates were directly reacted with metal oxides and formed copper or copper-zinc imidazolate frameworks. Copper-based mono- and bi-metallic imidazolate catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption, Fourier transform infrared spectra (FTIR), thermogravimetry (TG), XANES/EXAFS and CO2 adsorption capacities were measured. XANES spectra confirmed the presence of Cu(II) in Cu(im)2, Cu(mim)2, Cu(bim)2 and Cu2Zn(im)6, while Cu(I) in Cu2Zn(im)4. The Cu–O bond distance in Cu(im)2 sample was 2.00 Å with the coordination number of 2.4. It has been found that the CO2 adsorption capacity is directly related to the total pore volume and the specific surface area of the metal imidazolates. Cu(im)2 showed the highest CO2 adsorption capacity of 8.3 mmol g−1 measured at 273 K and 25 bar. The BET specific surface area of Cu(im)2 was 83.94 m2g−1 with the total pore volume of 22.2 cm3g−1.
關聯:
Nanoscience and Nanotechnology Letters 8(8), p.621-627
