Al2O3 and CeO2 had been used as Ru-catalyst support for ICCU-methanation, while CaO was used as the adsorbent for CO2 capture. The studies of different shapes of Al2O3 (powder, pellets and beads) showed that 5% Ru, 10% CaO/Al2O3 tableted powder (BASF) had the highest capacity of CO2 capture (11.18 g CO2/kg DFM); the highest methane production was obtained using 5% Ru, 10% CaO/Al2O3 pellets (TH100) (https://doi.org/10.1021/acs.iecr.6b01275). In addition, CO2 conversion was much higher using pellet Al2O3 support than other catalyst supports.
(https://doi.org/10.1021/acs.iecr.6b01275)
The following sentences are copied from this reference (https://doi.org/10.1016/j.ccst.2022.100052) regarding the influence of Ru-support on ICCU-methanation.
“In addition to the sorbent, support may also significantly affect the capture/methanation performances of Ru-based DFMs. For the widely used Al2O3 support, the effect of different types of γ-Al2O3 in powder, pellet, and sphere forms as the support for 5%Ru-10%CaO was investigated on their performance in the ICCC-Met process (Zheng et al., 2016). The Al2O3 carrier in pellets showed the best performance in methanation, which may be ascribed to the large surface area and pore size of the alumina pellets. Moreover, CeO2 was also used as the support for the Ru-based DFMs. Ru/CeO2 was physically mixed with MgO for the CO2 capture and methanation at 300°C (Sun et al., 2020). An optimum loading amount of Ru was found to be 5% on CeO2 due to its better stability over the ten cycles test. The CH4 yield and CO2 conversion reached 3.36 mol/kg and 79% for 5%Ru/CeO2-MgO, respectively, which were much higher than those on 2.5%Ru/CeO2-MgO (1.13 mol/kg and 39%) and 10%Ru/CeO2-MgO (2.31 mol/kg and 69%) after ten cycles operation. This was attributed to more oxygen vacancies generated in 5%Ru/CeO2-MgO because of the suitable metal-support interaction. A similar result was reported by Duyar et al. on 10CaO/Al2O3 (Duyar et al., 2015), in which the optimum loading amount of Ru was also 5%. Because of the large amount of sorbent used in the 10%Ru/CeO2-MgO (10%Ru/CeO2 to MgO mass ratio at 2:1), the CO2 uptake capacity and the CH4 yield were much higher compared to previously reported values as listed in Table 2. Besides, the influence of CeO2 morphologies (i.e., rod, particle, cube) on the CO2 capture and methanation performance was investigated by the same group (Sun, S. et al., 2022). CeO2 with rod morphology demonstrated the best performance in terms of the CH4 yield (0.33 mol/kg) and cyclically catalytic stability, possibly due to the higher Ru dispersion and support-metal interactions.”