CO2 capture performance of fluorinated porous carbon composite derived from a zinc-perfluoro metal-organic framework

Abstract

© 2022 The AuthorsNanoporous carbon composite was derived via carbonization of a zinc-perfluoro metal organic framework {MOF: Zn-hfipbb (H2hfipbb = 4,4′-(hexafluoroisopropylidene)bis(benzoic acid))}. The MOF-derivative exhibits extra 0.5 nm and 5.5 nm pores in addition to 0.45 nm pores from bare Zn-hfipbb. Accordingly, BET surface areas (560–1000 m2 g−1) of Zn-hfipbb derived material greater than for Zn-hfipbb (360 m2 g−1) were obtained by varying carbonization temperatures in the range 500–900 °C, which trend is opposite those of other MOF derivative. The C-F bond of di-trifluoro on the aromatic ligand in an MOF structure is strong; therefore, some fluorine remains as C-F within the carbon structure after carbonization. The obtained MOF derived composite (carbonized at 700 °C) exhibits 5-times higher CO2 uptake than the pristine MOF does at 1000 kPa and 20 °C, and exhibits higher heat of adsorption for CO2 at zero-coverage. A breakthrough experiment using a CO2/N2 gas mixture (1:99 M ratio) demonstrated that Zn-hfippb derivative (carbonized at 700 °C) exhibits a longer breakthrough time and is repeatedly used as CO2 adsorbents under high humid condition.