Catalytic oxidation of toluene using a facile synthesized Ag nanoparticle supported on UiO-66 derivative

In this paper, dispersed Ag nanoparticles supported on UiO-66 derivative were prepared and the effect of Ag loading on the structure and performance of the catalysts for toluene oxidation were studied. The characteristics of the catalysts were studied by XRD, SEM, TEM, HRTEM, BET, ICP-OES, XPS, UV-vis and in situ DRIFTS. It was observed that UiO-66 structure of 2 wt% Ag catalyst (2Ag-U) was not damaged. When Ag loading was further increased to 10 wt% (10Ag-U), framework of UiO-66 collapsed and uniform Ag nanoparticles were dispersed on the surface of support. Further increasing Ag to 14 wt% (14Ag-U), large Ag nanoparticles were observed, and Ag species migrated to the bulk phase of the support, resulting in the decrease of surface Ag content. The 10Ag-U catalyst showed excellent catalytic performance due to higher lattice oxygen and surface Ag⁰ content. In addition, in situ DRIFTS analysis was used to explore toluene-catalyzed intermediates. It was found that toluene was converted to benzaldehyde and benzoic acid, eventually forming CO₂ and H₂O.