Surface Species of Supported Ruthenium Catalysts in Selective Hydrogenation of Levulinic Esters for Bio-Refinery Application

Several supported noble metal catalysts were screened for the hydrogenation of methyl levulinate to c-valerolactone (GVL). Among these catalysts 5 % Ru/C showed the highest conversion of 95 % of methyl levuli- nate with 91 % selectivity to GVL. A detailed character- ization was carried out using TPR, XRD, XPS and BET techniques. XPS studies revealed that higher extent of Ru 0 species in case of carbon supported Ru was responsible for its higher hydrogenation activity as compared to Ru on other supports. Effect of process parameters such as tem- perature, H2 pressure, catalyst and substrate concentration and metal loading on methyl LA conversion and selectivity to GVL also has been studied. 5 % Ru/C catalyst was found to be stable up to five reuses.