Hydrogenation Catalysis by Hydrogen Spillover on Platinum‐Functionalized Heterogeneous Boronic Acid‐Polyoxometalates

The activation of molecular hydrogen is a key process in catalysis. Here, we demonstrate how polyoxometalate (POM)‐based heterogeneous compounds functionalized with Platinum particles activate H2 by synergism between a hydrogen spillover mechanism and electron‐proton transfer by the POM. This interplay facilitates the selective catalytic reduction of olefins and nitroarenes with high functional group tolerance. A family of polyoxotungstates covalently functionalized with boronic acids is reported. In the solid‐state, the compounds are held together by non‐covalent interactions (π–π stacking and hydrogen bonding). The resulting heterogeneous nanoscale particles form stable colloidal dispersions in acetonitrile and can be surface‐functionalized with platinum nanoparticles by in situ photoreduction. The resulting materials show excellent catalytic activity in hydrogenation of olefins and nitrobenzene derivatives under mild conditions (1 bar H2 and room temperature). Supramolecular colloids based on polyoxometalates functionalized with boronic acids are modified with Pt particles to yield high‐performance hydrogenation catalysts. Mechanistic studies reveal that the systems operate by a hydrogen spillover mechanism, enabling efficient hydrogenation of olefins to alkanes and nitroarenes to amines under mild conditions.