Effect of metal and promoter on CO2 capture and utilization through dry reforming of methane

Integrated CO2 capture and utilization (ICCU) through catalytic processes is a promising approach to mitigate greenhouse gas emissions and support net-zero targets. Among these, dry reforming of methane (DRM) converts CO2 and CH4 into syngas (H2/CO ≈ 1), a valuable feedstock for downstream processes such as Fischer-Tropsch synthesis. In this study, Rh-based hydroxyapatite (HAP) catalysts promoted with CeOx and FeOx were developed to evaluate their performance and molecular interactions under DRM and ICC-DRM conditions. The 0.2RhCeHAP catalyst showed superior activity and stability over 22 h at 700oC, surpassing its Fe-containing counterpart. In-situ FTIR and XPS analyses revealed that Rh–Ce interactions generated bridging oxygen species (Rhδ+-O-Ce2-x), stabilizing metallic Rh and enhancing CO₂ activation. In contrast, the Fe-containing catalyst formed surface FePO4, which hindered Rh reduction and caused rapid deactivation. Dual-functional materials (DFMs) were obtained by physically mixing catalysts with CaO, enabling efficient CO2 capture and in-situ conversion. Cyclic ICC-DRM tests confirmed long-term stability, with RhCeHAP based DFMs emerging as promising candidates for integrated CO2 capture and utilization.