Selective hydrogenation of levulinic acid in aqueous phase
Résumé
Levulinic acid (LevA) is obtained by an acidic treatment of carbohydrates issued from starch or cellulose [2] and identified by the US Department of Energy as one of the twelve interesting chemicals building blocks [3]. Indeed, a wide variety of high-value added products such as Gamma-valerolactone (GVL), 1,4-pentanediol (PDO) or methyltetrahydrofuran (MTHF) can be obtained by the selective hydrogenation of LevA. In this work, we evaluated the influence of several supported mono and bimetallic catalysts (Ru, Pd or Pt associated with Re) on the selectivity of the reaction. We have investigated the influence of (i) the nature of the support (C or TiO2); (ii) the mode of preparation of the monometallic catalysts (CE: Cationic Exchange; SI: Successive Impregnation; DP: Deposition-Precipitation); (iii) the ratio of the metallic promoter (Re/noble metal) and (iv) the operating conditions on the reaction rate and the selectivity into the desired products.