Phosphonates Meet Metal-Organic Frameworks: Towards CO2 Adsorption

Here we report a new highly microporous zirconium phosphonate material synthesized under solvothemal conditions. The specific Brunauer-Emmett-Teller (BET) surface area of the "unconventional metal-organic framework" (UMOF) is measured to be similar to 900 m(2)/g, after following an appropriate activation protocol. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) shows that the material bears a free -OH functionality on the phosphonate linker that may interact with CO2. CO2 adsorption isotherms were collected and a measured heat of adsorption of 31 kJ/mol was obtained. In addition, adsorption isotherms of CO2, N-2, and CH4 at 298 K combined with Ideal Adsorbed Solution Theory (IAST) show that the material can be expected to display high selectivities for uptake of CO2 versus N-2 or CH4.