Nanoparticles of Pd on Hybrid Polyoxometalate−Ionic Liquid Material: Synthesis, Characterization, and Catalytic Activity for Heck Reaction

By partial exchange of surface protons of a polyoxometalate (POM; H5PO40V2Mo10) by an ionic liquid (IL; butylmethylimidazolium, bmim+), a protonic IL-POM ([bmim]4HPO40V2Mo10) was obtained. Further exchange of this material with Pd2+ yields a final solid that HRTEM and EXAFS-XANES techniques show to be formed by very regular nanoparticles of PdO with ∼2 nm diameter, which are supported on 1 μm particles of IL-POM hybrid material. The PdO nanoparticles can be easily reduced to Pd, and the resultant material is an active and selective catalyst for the Heck reaction. The catalyst can be recycled, though metal leaching occurs in polar solvents. This can be an interesting material for performing Pd-catalyzed reactions in nonpolar solvents or for working in gas-phase reactions.