A membrane reactor was used for ICCU-RWGS research. The membrane consists of a ceramic phase of oxygen-ion conductor and the catalyst was LaNiO3 (LNO) or La0.9Ce0.1NiO3-δ (LCNO) catalyst (https://doi.org/10.1016/j.cej.2019.122182). The catalytic membrane has two functions, including CO2 separation and catalytically converting the separated CO2 into CO. As indicated in the following figure, the separated CO2 was converted to CO and H2O using H2 as the sweeping gas.
https://doi.org/10.1016/j.cej.2019.122182
The presence of Ni was important to enhance CO production yield. In addition, the authors reported that the dual functional catalytic membrane produced a CO2 flux of 4.25 ml/min-1 cm-2, which was 4 times higher than the single membrane separation using H2 as the sweep gas. Up to 70 h stability (indicated in the above figure) was also reported with CO2 conversion of 57% and the CO production rate of 2.41 ml min-1 cm-2 at 750 °C. The authors also suggested that the flow rate of H2 should match the permeation rate of CO2 during the whole process.