Fast synthesis of Al fumarate metal-organic framework as a novel tetraethylenepentamine support for efficient CO2 capture

Abstract

In this study, a rapid synthesis of Al fumarate metal-organic framework (AlFu) at 25 °C for 1 min has been reported. The synthesized AlFu has been impregnated by different amounts of tetraethylenepentamine (TEPA) to build novel CO2 adsorbents. AlFu before and after functionalization was characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and nitrogen adsorption/desorption isotherms (BET). The results showed the introduction of TEPA into AlFu was successfully achieved by impregnation. The CO2 adsorption performances of AlFu and TEPA@AlFu were investigated by the TGA method. The effect of adsorption temperature, TEPA loading and CO2 partial pressure on the adsorption performance was studied. The results showed that the optimum adsorption temperature of TEPA@AlFu is 75 °C, and increasing the loading amount of TEPA will enhance the CO2 adsorption capacity and decrease the adsorption rate. High CO2 partial pressure is good for the adsorption process, and the highest CO2 adsorption capacity of 4.10 mmol/g was obtained at 75 °C in a pure CO2 atmosphere for the AlFu loaded with 60 wt% TEPA. The studies of adsorption kinetics show the fractional-order kinetic model fitted well with the CO2 adsorption experiment data. Moreover, the CO2 adsorption capacity of 60TEPA@AlFu sorbent declined only 2.81% after 10 adsorption-desorption cycles tested in the temperature range of CO2 adsorption (75 °C) and desorption (110 °C).