Dual functional materials containing BaO as the sorbent for CO2 capture and Ni as the catalytic sites for CO2 utilisation were reported (https://doi.org/10.1016/j.jcou.2020.101201), while the reduction agent for CO2 utilisation was methane. The DFMs were prepared by coprecipitation of Ni and Ba salts using colloidal silica as the support precursor. The DFMs showed a relatively low capacity of CO2 capture (<0.25 mmol/g), and the conversion of CO2 and CH4 was also low (<15%). This is mainly due to the sorbent used in this work. BaO has a relatively low capacity of carbon capture. The concentrations of gases during the cyclic ICCU are shown below. The ICCU concept has been successfully demonstrated at 600 °C. It is noted that very high H2/CO ratio was produced during the CO2 utilisation stage, indicating that there was a significant dissociation of CH4. In addition, CO formation is clearly observed during the 2nd cycle of CO2 capture. The authors claimed that this was due to the decomposition of the CO3-retained species on the DFMs. However, other authors (doi:10.1126/sciadv.aav5077) ascribed the formation of CO during the carbon capture stage as the reaction between CO2 and deposited carbon.
https://doi.org/10.1016/j.jcou.2020.101201
Carbon deposition on the DFMs after ICCU-DRM has been confirmed using Raman analysis, as indicated below.
