Enhanced Catalytic Performance of UiO-67 Supported Pd Catalyst for Toluene Degradation

Owing to the intrinsic nature of the uniformed topologies and ultrasmall Zr₆ nodes of Zr-MOFs, herein, we employed Zr-MOFs (UiO-66 and UiO-67), as opposed to the support of traditional ZrO₂, to prepare the Pd catalysts for toluene degradation. Compared with the catalysts of Pd/UiO-66 and Pd/ZrO₂, Pd/UiO-67 catalyst boosted an excellence catalytic performance for toluene degradation, giving the lowest T_90% value of 235 °C with long-term stability. With the assisting of the cavity confinement of Zr-MOFs, Pd nanoparticles are prone to be encapsulated in the 3D frameworks of Zr-MOFs, and the bigger micropores of UiO-67 are more conducive to the formation of larger Pd nanoparticles. The in situ FT-IR results further declared that although the active sites are partly sacrificed due to the larger Pd nanoparticles formed in UiO-67, the stable adsorbed toluene on Pd/UiO-67 boosted the quick degradation of toluene in the reaction interval even without undergoing intermediate processes of benzoate and benzaldehyde.

Graphical Abstract

UiO-66, UiO-67 and ZrO₂ were employed to prepare the Pd catalysts for toluene degradation, Pd/UiO-67 catalyst boosted an excellence catalytic performance with long-term stability.