Continuous CO₂ Capture and Selective Reduction to CO over Main-Group Dual-Functional Materials

CO₂ capture and reduction to CO using dual-functional materials (DFMs) has recently attracted significant attention as a promising strategy for carbon capture and utilization. DFMs generally comprise basic metals for CO₂ capture and transition metals for CO₂ conversion. Herein, we successfully developed a DFM (Cs/Al₂O₃) consisting only of main-group elements, which enabled continuous and selective CO production with high CO₂ conversion (89%) and CO selectivity (99%). Notably, Cs/Al₂O₃ exhibited better CO₂ capture and CO formation performance than platinum-group metal-based DFMs under isothermal conditions at 500 °C, even in the presence of O₂ during the CO₂ capture phase. Comprehensive characterization suggested that single Cs atoms were uniformly dispersed on Al₂O₃, forming adjacent sites in close proximity. Based on operando infrared analysis, including modulation excitation spectroscopy, the monodentate carbonate species adsorbed during CO₂ capture reacted with H₂ and yielded gas-phase CO.