Selective Levulinic Acid Hydrogenation in Presence of Hybrid Dendrimer‐Based Catalysts. Part II: Bimetallic

Abstract Various heterogeneous bimetallic Ru, Rh, Pd and/or Cu‐containing catalysts, based on dendrimer‐silica mesoporous hybrid supports, are successfully synthesized, using co‐complexation method, and characterized by transmission electron microscopy and X‐ray photoelectron spectroscopy. The catalysts obtained are examined in the aqueous hydrogenation of levulinic acid and its esters to γ‐valerolactone. The catalyst activity and selectivity on γ‐valerolactone are strongly dependent on the nature and ratio of metal used, and PdRu bimetallic catalysts are found to be the most effective. Quantitative or near to quantitative yields of γ‐valerolactone can be achieved for all PdRu catalysts and substrates tested within 2 hours, with maximum TOF value of 4500 h −1 . Such high efficiency is provided by especial nanoparticle structure, consisted of Pd core and RuPd shell, and synergistic effect between Ru and Pd in alloy.