Catalytic Hydrogenation of Arenes in Water Over In Situ Generated Ruthenium Nanoparticles Immobilized on Carbon

We describe a tandem process to generate active Ru nanoparticles (≈7 nm) immobilised in situ on carbon from an organometallic precursor and formic acid to afford the hydrogenation of a wide range of arenes and heteroarenes in yields up to 72 % with high conversions and selectivities for the desired products. The hydrogenation of several substrates analogous to lignin-derived fragments to the corresponding alicyclic products was also achieved. Our experimental investigations evidenced that the observed enhanced activity for arene hydrogenation was driven by the unique structural advantages of the organometallic precursor to activate formic acid, in which the presence of a nitrogen ligand is crucial to achieve a high catalytic activity. TEM analysis revealed the formation of Ru0 nanoparticles, and Hg0 poisoning experiments support the heterogeneous nature of the active catalyst.