Simplified synthesis of Pt-MnO_x supported on three dimensional Co₃O₄ for catalytic removal of toluene

In this study, a simplified method was developed for synthesizing Pt-(MnO_x)/three-dimensional (3D)-Co₃O₄ catalysts. This approach represents a convenient alternative to the typical procedure of initially synthesizing nanoparticles (NPs) and subsequently depositing them onto supports. The Pt₁-(MnO_x)₁/3D Co₃O₄ catalyst, with a molar ratio of Pt:Mn=1:1, demonstrated excellent catalytic efficacy at a comparatively low reaction temperature and displayed commendable thermal stability during prolonged operation in the deep oxidation of toluene. The T₉₀ (temperature required for 90 % conversion) of Pt₁-(MnO_x)₁/3D Co₃O₄ was merely 163 °C. Characterization analysis revealed that the catalyst's remarkable catalytic efficiency is attributed to the elevated concentration of oxygen vacancy defects on Pt₁-(MnO_x)₁/3D Co₃O₄ and its low-temperature reducibility. In situ DRIFTS analysis was conducted to investigate the possible reaction pathway of Pt₁-(MnO_x)₁/3D Co₃O₄. The results indicated that the rapid dehydrogenation of methyl and the demethylation of toluene facilitate the cleavage of the benzene ring on the Pt₁-(MnO_x)₁/3D Co₃O₄ catalyst, due to the abundant absorption of oxygen species. This process enhances the catalytic combustion of toluene.