Tunable C2 Products via Photothermal Steam Reforming of CO2 over Surface-Modulated Mesoporous Cobalt Oxides

The conversion of CO2 to high-value productsby renewableenergy is a promising approach for realizing carbon neutralization,but the selectivity and efficiency of C2+ products arenot satisfying. Herein, we report the controllable preparation ofhighly ordered mesoporous cobalt oxides with modulated surface statesto achieve efficient photothermal water-steam reforming of CO2 to C-2 products with high activity and tunableselectivity. Pristine mesoporous Co3O4 exhibitedan acetic acid selectivity of 96% with a yield rate of 73.44 mu molg(-1) h(-1). By rationally modifyingmesoporous Co3O4 surface states, mesoporousCo(3)O(4)@CoO delivered a radically altered similar to 100%ethanol selectivity with a yield rate of 14.85 mu mol g(-1) h(-1). Comprehensive experiments revealed that thepH value could strongly influence the selectivity of C-2 products over mesoporous cobalt oxides. Density functional theoryverified that reduced surface states and rich oxygen vacancies onsurface-modified mesoporous cobalt oxides could facilitate furthervariation of C-2 products from acetic acid to ethanol.

Automated summary

In this study, highly ordered mesoporous cobalt oxides with modulated surface states were prepared for efficient photothermal water-steam reforming of CO2 to C-2 products with high activity and tunable selectivity. The mesoporous Co3O4 exhibited a high acetic acid selectivity of 96% and a yield rate of 73.44 mu mol g(-1) h(-1), while the surface-modified mesoporous Co(3)O(4)@CoO achieved 100% ethanol selectivity with a yield rate of 14.85 mu mol g(-1) h(-1). The pH value was found to strongly influence the selectivity of C-2 products, and density functional theory confirmed the role of reduced surface states and rich oxygen vacancies in promoting the variation of C-2 products from acetic acid to ethanol.