Valeric Biofuel Production from γ-Valerolactone over Bifunctional Catalysts with Moderate Noble-Metal Loading

SiO₂ -Al₂ O₃ -supported Ru, Ir and Pt-based catalysts with moderate metal loading (1 %) were tested for the first time in the production of pentyl valerate (PV) in liquid phase from γ-valerolactone, pentanol (in excess) and H₂ . The acidity of these bifunctional catalysts, plays a key role in the one-pot process comprising two consecutive acid-catalyzed reactions and a metal-catalyzed one. Metal dispersion also shown to be relevant for the conversion of the pentyl pentenoate intermediate into PV by hydrogenation over the metal sites. Pt/SA catalyst with the highest surface acidity and metal dispersion reached optimal GVL conversion with a PV yield of 90.0 % after 10 h, exhibiting a PV productivity of 300 mmol/g_M .h, i. e. a value between three and four times higher than the best result reported until now (91.8 mmol/g_M .h). These findings highlight the potential that noble metal-based catalyst with moderate metal loading have in the valorization of biomass-derived platform molecules such as γ-valerolactone.