New Palladium - ZrO Nano-Architectures from Thermal Transformation of UiO-66-NH for Carbonylative Suzuki and Hydrogenation Reactions.

The new nanocomposites, Pd/C/ZrO , PdO/ZrO and Pd/PdO/ZrO , were prepared by thermal conversion of Pd@UiO-66-Zr-NH (MOF) in nitrogen or air atmosphere. The presence of Pd nanoparticles, uniformly distributed on the ZrO or C/ZrO matrix, was evidenced by transmission electron microscopy, scanning electron microscopy (SEM), Raman and X-ray Photoelectron Spectroscopy (XPS) methods. All pyrolysed composites retained the shape of the MOF template. They catalyze carbonylative Suzuki coupling under 1 atm CO with an efficiency significantly higher than the original Pd@UiO-66-Zr-NH . The most active PdO/ZrO composite, formed benzophenone with TOF up to 1600 h , while by using Pd@UiO-66-Zr-NH , much lower TOF values, 51-95 h , were achieved. After the reaction, PdO/ZrO was recovered with the same composition and catalytic activity. Very good results were also obtained in the transfer hydrogenation of benzophenones to alcohols with Pd/C/ZrO and PdO/ZrO catalysts under microwave irradiation.