Enhanced CH<sub>4</sub> Production from CO<sub>2</sub> Hydrogenation on γ‑AlOOH-Supported\nCobalt Catalyst\nwith Abundant Surface Coordination Unsaturated Oxygen Atoms

Under the context of growing greenhouse effect, it is\nof great\ninterest to hydrogenate CO<sub>2</sub> into high-valuable hydrogen-containing\nchemicals (e.g., CH<sub>4</sub>) which can be further used as fuels,\nhydrogen carriers, and raw materials for industry. Herein, we first\nfabricate a catalyst support denoted by Al-D0, which is composed of\nboehmite (γ-AlOOH), and then increase the content of surface\ncoordination unsaturated O (O<sub>uns</sub>) atoms on Al-D0 to form\nanother catalyst support denoted by Al-D60. During CO<sub>2</sub> hydrogenation\nby H<sub>2</sub>, the Al-D0-supported Co catalyst (Co/Al-D0) and the\nAl-D60-supported Co catalyst (Co/Al-D60) show different performance.\nCO<sub>2</sub> conversion in CO<sub>2</sub> hydrogenation on Co/Al-D60\n(22.10%) is higher by 10.94 times than that on Co/Al-D0 (2.02%). Only\nCO is produced from CO<sub>2</sub> hydrogenation on Co/Al-D0, but\nCo/Al-D60 enhances the CH<sub>4</sub> production from CO<sub>2</sub> hydrogenation. The more abundant O<sub>uns</sub> on Co/Al-D60 facilitates\nCO<sub>2</sub> adsorption and activation on Co/Al-D60. This leads\nmore activated CO<sub>2</sub> to participate in the hydrogenation\nreaction, thus increasing CO<sub>2</sub> conversion on Co/Al-D60.\nThe more activated CO<sub>2</sub> could easily capture H from H<sub>2</sub> dissociation, thus enhancing CH<sub>4</sub> production on\nCo/Al-D60. The present work provides a new strategy for developing\na more efficient catalyst for CO<sub>2</sub> hydrogenation to high-value\nhydrogen-containing chemicals.