Carbon dioxide adsorption properties of K-Al-Fe–based oxides prepared from a porous polymer monolith template

K-Al-Fe–based oxides with bimodal pores in the meso- and macro-size range were synthesized using spherical porous polymer monolith templates containing bicontinuous pore structures for use as a CO2 adsorbent. The porous K-Al-Fe–based oxides showed higher CO2 adsorption capacity than the corresponding non-porous sample. Lowering the calcination temperature during porous K-Al-Fe–based oxide synthesis from 900 °C to 450 °C led to further increases in CO2 adsorption capacity. The CO2 adsorption capacity of this porous K-Al-Fe–based oxide was significantly enhanced after H2O vapor treatment. FT-IR analysis showed that the treatment allowed for the formation of an additional CO2 capture species. The improved CO2 adsorption capacity was due to the change in the adsorption mode of CO2 from the monodentate carbonate to a bicarbonate after a reaction with H2O vapor. The thermal and structural stability of the porous K-Al-Fe–based oxide was maintained even after treatment in H2O vapor.