Influence of supported alkali/alkaline-earth metals on ICCU-DRM

In this report (, transition metal free dual functional materials were used for ICCU-RWGS. CaO-only was reported to have both functions of CO2 capture and the conversion of captured CO2. Therefore, using transition metal free materials for CO2 conversion open a new strategy for CO2 reduction, saving the cost of materials and also improving environmental benefits.

Na, K and Ca were loaded on Al2O3 support and used for ICCU-RWGS. The results (shown in the following figure) indicated that Na and K were more effective than Ca, in terms of the production of CO. In addition, the bare Al2O3 showed no reaction reactivities in relation to CO2 conversion. It is noted that the ICCU-RWGS experiments were carried out at 450 °C and the flow rate of hydrogen was 100 ml/min. The authors claimed that the transition metal free DFMs were active at lower temperatures compared to previously reported CaO (10.1016/j.ccst.2021.100001). However, it is noted that at temperatures higher than 550 °C using CaO, the capacity of CO2 capture and the yield of CO production is much higher.


“Figure – Concentration profiles during integrated CO2 capture and conversion with (a) Na/Al2O3, (b) K/Al2O3, (c) Ca/Al2O3, and (d) Al2O3 at 450 °C and an H2 flow rate of 100 mL/min.” (


The authors further quantified the capacity of CO2 capture and the selectivity to CO. As indicated below, high conversion of CO2 (>90%) and CO selectivity (>90%) were obtained. At 450 °C, the capacity of CO2 capture followed this order: K/Al2O3 > Na/Al2O3 > Ca/Al2O3 > Al2O3.


“Figure – CO2 capture and conversion performance of the prepared DFMs at 450 °C and an H2 flow rate of 100 mL/min. “(

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