Fig. 3: Catalytic performance of HEI/CeO₂ in the CO₂-ODP.

Reaction conditions: catalyst amount, 100 mg; gas feed, C₃H₈:CO₂:He = 5:5:10 mL·min⁻¹; temperature, 600 °C. a–c Time course of (a) C₃H₈ conversion, (b) C₃H₆ selectivity in hydrocarbons, and (c) CO₂ conversion. d Relative coke amount accumulated by O₂-TPO of the spent catalysts after the time stream of a in CO₂-ODP at 600 °C. e Metal dispersions comparison of fresh and spent catalysts. f Reusability of HEI/CeO₂ in repeated long catalytic runs with regeneration procedure (CO₂:He = 5:10 mLmin⁻¹ for 2 h, then H₂:He = 5:10 mLmin⁻¹ for 0.5 h at 600 °C between each cycle). g–i Comparison of the catalytic performances with those of reported systems (values indicate references in Supplementary Tables 5, 6): g C₃H₈ conversion vs. C₃H₆ selectivity, (h) C₃H₆ yield vs CO₂ conversion, (i) specific activity of C₃H₆ production (mL_C3H6 min⁻¹ g_{AM(active metal)}⁻¹) vs. mean catalyst life (τ = k_d⁻¹: reciprocal deactivation constant).