Ultralow-loading Pt/Ni-supported CeO2 catalysts for efficient propane dry reforming: Enhanced oxygen vacancies and metal-support interaction for superior syngas production

Dry reforming of propane (PDR) has attracted increasing attention for syngas production due to its lower energy demand compared to methane dry reforming (DRM). In this study, a series of Pt/Ni-supported CeO₂-based catalysts with ultralow metal loadings (0.2 wt% Pt and 0.6 wt% Ni) was synthesized via a one-step hydrothermal method by utilizing H₂ as a structure-directing agent and PEG, EG as the dispersants. The optimized catalyst of Pt_0·2/Ni_0.6@CeO₂^−D-1H₂ demonstrates exceptional catalytic performance (C₃H₈, CO₂ conversions of 39.4 and 94.9 %; syngas productivity of both 30 mmol·g_cat⁻¹·h⁻¹) and reaction stability (pass through 30 h's reaction) at 600 °C. Comprehensive characterization techniques, including XRD, H₂-TPR, CO₂-TPD, XPS, and HRTEM, reveal that the introduction of H₂ and dispersants (PEG and EG) significantly enhance the oxygen vacancy concentration, which promoted CO₂ adsorption and activation. Moreover, they can also modulate the catalyst morphology structure, which effectively inhibits the sintering of active metals through promoting the anchoring of active metals and strengthening the interaction between Ni²⁺ and the support. In-situ FTIR analysis suggested a plausible reaction mechanism: CO₂ initially adsorbs on the catalyst surface to form carbonate species, which are subsequently transformed into formate intermediates and finally decomposed into CO and OH∗ species. Generally, this study demonstrates the development of a highly efficient Pt/Ni-supported CeO₂ catalyst achieving superior syngas production through enhanced oxygen vacancy generation, optimized metal-support interaction, which would contribute to other highly efficient catalyst designs.