CO₂-assisted oxidative dehydrogenation of propane enabled by the second metal promoter of Ga on Pt/silica catalysts

BACKGROUND: Carbon dioxide-assisted propane dehydrogenation (CO₂-ODP) is a promising advanced technology for propylene production. However, a significant challenge still remains in advancing the adsorption and activation of propane and CO₂, as hydrogenolysis and oligomerization isomerization reactions severely constrain propylene production. RESULTS: In this work, we introduce Ga as a second metal promoter into Pt/SiO₂ catalysts, effectively promoting the dispersion of active particles and significantly reducing their size, thereby enhancing their catalytic activity. Meanwhile, the impregnation of Ga also promotes the activation of CO₂, ultimately accelerating the reverse gas–water shift reaction. CONCLUSION: The propylene yield and CO₂ conversion of Pt–Ga₁/SiO₂ catalyst increased up to 40.45% and 45.10%, respectively, which were 17.54 and 6.62 times higher than those of the pristine SiO₂–Pt catalyst at weight hourly space velocity (WHSV) = 3.1 h⁻¹. Most notably, the C₃H₆ selectivity of SiO₂–Pt/Ga₁ catalyst remarkably achieved an impressive value of 99.04%, which was much higher than that of other bimetallic-based catalysts, thus providing valuable guidance for the rational development of bimetallic highly active CO₂-ODP catalysts.