The new nanocomposites, Pd/C/ZrO2 , PdO/ZrO2, and Pd/PdO/ZrO2 , were prepared by thermal conversion of Pd@UiO-66-Zr-NH2 (MOF) in nitrogen or air atmosphere. The presence of Pd nanoparticles, uniformly distributed on the ZrO2 or C/ZrO2 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-NH2 . The most active PdO/ZrO2 composite, formed benzophenone with TOF up to 1600 h-1 , while by using Pd@UiO-66-Zr-NH2 , much lower TOF values, 51-95 h-1 , were achieved. After the reaction, PdO/ZrO2 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/ZrO2 and PdO/ZrO2 catalysts under microwave irradiation.
Keywords: MOF pyrolysis g; PdO/ZrO2 nanocomposites; carbonylative Suzuki coupling; palladium; transfer hydrogenation reactions.
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