The integrated carbon capture and utilization (ICCU) process offers a viable solution by eliminating the additional costs and safety risks associated with CO2 transportation and storage, thereby enhancing overall economic feasibility. Nevertheless, this approach still encounters several challenges, including high reaction temperatures, difficulties in CO2 activation under low-temperature conditions, and an unclear reaction mechanism, all of which necessitate further in-depth investigation. In this study, the ICCU process was enhanced at the microscopic level by facilitating the formation of surface carbon species and in-situ hydrogenation on the surface of dual functional materials (DFM). A pre-reduction treatment was employed to construct the Co based DFM, thereby achieving low-temperature CO2 activation (220 °C) and in-situ immobilization. By modulating structural variations within the DFMs, the regulation of the ratio of CoO-support interface and Co0 was realized, enabling the regulation of CO2 capture capacity and the type of carbon species. On this basis, the reaction pathways of CO2/H2 during the CO2 capture and methanation stages were elucidated, along with the mechanistic role of the CoO-support interface and highly dispersed cobalt species. The presence of the CoO-support interface was found to significantly enhance the CO2 adsorption capacity and carbon species stability, effectively preventing the desorption of surface carbon species during the nitrogen purging stage. Additionally, the strong interaction between cobalt and support ensured the high dispersion of CoO and Co0 on the DFM surface, providing the necessary conditions for the efficient conversion of carbon species during the methanation stage.
