Acetate-assisted Synthesis of Chromium(III) Terephthalate and Its Gas Adsorption Properties

摘要

We report a facile synthetic approach of high-quality chromium(III) terephthalate [MIL-101(Cr)] by acetateassisted method in the absence of toxic HF. Results indicate that the morphology and surface area of the MIL- 101(Cr) can be tuned by modifying the molar ratio of acetate/Cr(NO3)3. The Brunauer-Emmett-Teller (BET) surface area of MIL-101(Cr) synthesized at the optimized condition can exceed 3300 m2/g. It is confirmed that acetate could promote the dissolution of di-carboxylic linker and accelerate the nucleation ratio. So the pure and small size of MIL-101(Cr) with clean pores can be obtained. CO2, CH4 and N2 adsorption isotherms of the samples are studied at 298 K and 313 K. Compared with the traditional method, MIL-101(Cr) synthesized by acetate-assisted method possess enhanced CO2 selective adsorption capacity. At 1.0 bar 298 K, it exhibits 47% enhanced CO2 adsorption capacity. This may be attributed to the high surface area together with clean pores of MIL-101(Cr).