Continuous CO 2 Capture and Selective Reduction to CO over Main-Group Dual-Functional Materials

CO 2 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 CO 2 capture and transition metals for CO 2 conversion. Herein, we successfully developed a DFM (Cs/Al 2 O 3 ) consisting only of main-group elements, which enabled continuous and selective CO production with high CO 2 conversion (89%) and CO selectivity (99%). Notably, Cs/Al 2 O 3 exhibited better CO 2 capture and CO formation performance than platinum-group metal-based DFMs under isothermal conditions at 500 °C, even in the presence of O 2 during the CO 2 capture phase. Comprehensive characterization suggested that single Cs atoms were uniformly dispersed on Al 2 O 3, forming adjacent sites in close proximity. Based on operando infrared analysis, including modulation excitation spectroscopy, the monodentate carbonate species adsorbed during CO 2 capture reacted with H 2 and yielded gas-phase CO.