Preparation and catalytic properties of Pd nanoparticles supported on micro-crystal DUT-67 MOFs

Zr-based MOFs usually feature exceptionally high thermal and chemical stability, which suggests that composites of noble metals and Zr-based MOFs could have wide industrial applications. In this work, we report the synthesis and characterization of Pd nanoparticles (of three different loadings: 0.3%, 0.5% and 1.0%) supported on micro-crystal DUT-67 MOFs. Via SEM, TEM and XPS characterization methods, it was found that the Pd nanoparticles were well dispersed on the interface of the MOF micro-crystals, with a diameter of 3.5 nm, and both the dangling organic groups and the cavities of the MOFs play important roles. Furthermore, PXRD, IR, TGA and N2 adsorption measurements confirmed that the composites are very robust. Studies on the catalytic properties indicated that they have good catalytic performance with a conversion of 99% and selectivity of 89% in the Suzuki coupling reaction. By a series of explorations, we found the best catalytic conditions are an ethanol–water mixed solvent as the medium, K2CO3 as the base and a temperature of 70 °C. Moreover, good catalytic properties were also shown for the hydrogenation of nitrobenzene, where the optimum temperature was 60 °C, and a conversion of 99% and selectivity of 99% were achieved.