Photo-Thermal Synergistic Catalytic Oxidative Dehydrogenation of Propane over NiO Nanoparticle-Decorated Graphitic Carbon Nitride

The oxidative dehydrogenation of propane (ODHP) catalyzed by oxygen offers several advantages, including resistance to carbon deposition and low energy consumption. However, achieving high propylene selectivity at industrially relevant conversions remains challenging, as existing catalysts typically require temperatures exceeding 500 °C, promoting over-oxidation to COx. In this study, we developed a NiO nanoparticle-decorated graphitic carbon nitride catalyst (NiO@CN-600) via thermal polymerization–oxidation for photo-thermal synergistic ODHP. At 430 °C, thermal catalysis achieved a propane conversion of 14%. Remarkably, introducing light irradiation boosted conversion to 24%, a 10% increase. Further experimental results reveal that the photo-thermal synergistic catalysis can be described by the following mechanism: initial thermal energy provides sufficient activation energy, enabling the reaction to overcome the energy barrier and proceed smoothly. Simultaneously, the introduction of light energy enhances the activity of lattice oxygen, making it more likely to detach from the lattice and form oxygen vacancies, which in turn boosts the efficiency of the oxidation reaction on the catalyst surface.