Synthesis, Characterization and CO2 Adsorption of Cr(III)-Based Metal-Organic Framework

Abstract

Chromium(III)-based metal-organic framework was prepared by using a tritopic bridging 1,3,5-Tris(4-carboxyphenyl) benzene ligand as a linker and chromium as metal that forms a secondary building unit, by solvothermal method. Continuous weight loss of Cr-MOF sample in the entire temperature range was related to loss of desorption of adsorbed gases from pores and cavities, removal of guest molecules such as N,N-dimethyl formamide, and framework disintegration. Specific surface area was found to be 420 m2/g and significant steep raise in the isotherm at partial pressure >0.2 indicates microporous character of the sample. The CO2 adsorption capacity of Cr-MOF sample measured at 298 K and partial pressure of 0.9 atm was found to be 3.5 wt.%. Temperature elevation from 298 to 343 K decreases adsorption capacity according to the Le-Chatelier's Principle. The CO2 adsorption increases linearly as the pressure increases from 0 to 0.9 atm is due to relatively weak adsorption sites and homogeneity.