Tunable C 2 Products via Photothermal Steam Reforming of CO 2 over Surface-Modulated Mesoporous Cobalt Oxides.

The conversion of CO 2 to high-value products by renewable energy is a promising approach for realizing carbon neutralization, but the selectivity and efficiency of C 2+ products are not satisfying. Herein, we report the controllable preparation of highly ordered mesoporous cobalt oxides with modulated surface states to achieve efficient photothermal water-steam reforming of CO 2 to C 2 products with high activity and tunable selectivity. Pristine mesoporous Co 3 O 4 exhibited an acetic acid selectivity of 96% with a yield rate of 73.44 μmol g -1 h -1 . By rationally modifying mesoporous Co 3 O 4 surface states, mesoporous Co 3 O 4 @CoO delivered a radically altered ∼100% ethanol selectivity with a yield rate of 14.85 μmol g -1 h -1 . Comprehensive experiments revealed that the pH value could strongly influence the selectivity of C 2 products over mesoporous cobalt oxides. Density functional theory verified that reduced surface states and rich oxygen vacancies on surface-modified mesoporous cobalt oxides could facilitate further variation of C 2 products from acetic acid to ethanol.