Carbon Dioxide Adsorption on Iron (III) Oxide Pillarized Na-Montmorillonite

Abstract

Iron (III) oxide (Fe2O3) pillarized Na-montmorillonite (NaMMT) was prepared by ion-exchanging and calcining three different concentrations (0.025, 0.05, and 0.075 M) of Fe(OH)3 with NaMMT. The obtained materials were then examined for its ability to capture carbon dioxide, using thermogravimetric methods. The structural, compositional, and textural changes caused by pillarization were also examined using XRD, XRF, FTIR, and BET-BJH. The results showed that NaMMT-0.025 (pillared using 0.025 M of Fe(OH)3) and NaMMT-0.075 exhibit superior adsorption capacity compared to NaMMT, with NaMMT-0.025 having the greatest capacity. By contrast, NaMMT-0.05 registers a decrease in the amount of CO2 adsorbed, compared to NaMMT. Using XRF, it was shown that the amount of Fe2O3 present in the samples correspond to the concentration of Fe(OH)3 used in ion-exchange. XRD results shows that the interlayer space of NaMMT barely changed after addition of Fe2O3. Using FTIR, successful pillarization of Fe2O3 is confirmed, and by combining it with BET-BJH, it shows that addition of Fe2O3 could enhance carbon capture by creating favourable pore structures. Overall, it shows that adding an appropriate amount of Fe2O3 to montmorillonite will enhance CO2 adsorption.