Pt Nanoparticles Supported on the Graphitic Carbon Nitride/CeO₂ Nanocomposite as a Catalyst for the Oxidation of Toluene

The Pt/CeO2 catalyst is widely studied for the catalytic purification of volatile organic compounds (VOCs) due to its distinctive nanoscale features, including strong metal–support interaction (SMSI), abundance of oxygen vacancies, and excellent redox properties, and stability of CeO2 nanomaterials. However, significant challenges remain, including the poisoning effect of water vapor and the excessive strengthening of the SMSI, which lead to an increased Pt valence state and loss of activity. In this work, we present a g-C3N4–CeO2 nanocomposite-supported Pt catalyst (Pt/CN–CeO2) for enhancing the catalytic oxidation of toluene. The electron-rich material, g-C3N4, interacts with CeO2 to generate additional oxygen vacancies and donates electrons to Pt nanoparticles, facilitating the formation of active Pt0 species and improving the catalytic efficiency of toluene oxidation. The optimized Pt/CN–CeO2 nanocomposite catalyst achieves a 90% toluene conversion at 203 °C, in contrast to 254 °C required for the conventional Pt/CeO2 catalyst under the same conditions. In addition, the optimized Pt/CN–CeO2 nanocomposite catalyst exhibits strong resistance to water poisoning and exceptional stability for toluene oxidation, consistently maintaining a toluene conversion rate above 99% at 210 °C for 50 h. These findings offer valuable insights into the design of advanced catalytic materials at the nanoscale and facilitate the application of Pt/CN–CeO2 nanocomposite catalysts in environmental catalysis.