Novel dual functional materials containing Fe and Co as catalytic sites and CaO as the sorbent were investigated for ICCU-RWGS (https://doi.org/10.1039/D0EE03320K). The DFMs were prepared by a one-pot sol-gel method. The authors reported a high capacity of CO2 capture (~9 mmol/g). The addition of MgO and highly dispersed Fe and Co improved the stability of CaO in terms of metal sintering (as shown in the following figure). In addition, the doped Fe and Co oxides supported extra oxygen vacancies to promote CO2 adsorption. The ICCU-RWGS was performed at 650 °C and nearly 90% CO2 conversion and 100% CO selectivity were reported.
“10 cycle CO2 capture and in situ conversion performance of Fe5Co5Mg10CaO at 650 °C in one fixed-bed column. (a) CO2 capture capacity (mmol g−1) and conversion efficiency (%) and (b) the molar flow rate of CO and CO2 in the outlet gas after the conversion.” https://doi.org/10.1039/D0EE03320K
The authors further proposed a heterojunction-redox mechanism (as shown in the following figure) to explain ICCU-RWGS process.