SiO2‐Al2O3‐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/gM.h, i. e. a value between three and four times higher than the best result reported until now (91.8 mmol/gM.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.

This study reports the selective obtaining of butanediols (BDO), widely used in the polymer and synthetic rubber industry, by CÀ O hydrogenolysis of erythritol. The effect of the support on catalytic activity and selectivity to BDO was exhaustively studied using Ir/ReO x catalysts supported on SiO 2 , Al 2 O 3 , activated carbon, CeO 2 , TiO 2 and ZrO 2 . The catalysts were thoroughly characterized and it was found that the physicochemical, redox and acidic properties of the supports notably influenced the metal dispersion, reducibility of the species and particle sizes.The most active and selective catalyst was Ir/ReO x /TiO 2 (maximum BDO yield of 53 %), favoring CÀ O hydrogenolysis and minimizing CÀ C scissions and dehydration reactions. This superior performance was attributed to the formation of small clusters with an intimate contact between Ir and partially oxidized Re species (mainly Re + IV ) that favors the appropriate adsorption of erythritol on ReO 2 and the further interaction with H 2 adsorbed on Ir 0 to render BDO.

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The C-O hydrogenolysis of Erythritol to Butanodiols was studied in aqueous solution at 473 K and 25 bar of H2 using Rh/ReOx/TiO2 and the monometallic Rh/TiO2 and ReOx/TiO2 catalysts. The solids were characterized by temperature programmed reduction (TPR), TEM and XPS. TPR and XPS showed that ReOx species are close to Rh particles leading to reduction at lower temperature than Re on monometallic catalyst. However, some segregated Rhenium species were suspected by TPR profile for the bimetallic catalyst and detected by TEM.  Re/TiO2 exhibited low activity forming only products from dehydration and epimerization. Although Rh/TiO2 showed high activity (total conversion at 14 h), was more selective to C-C cleavage leading to lower carbon products. Rh/ReOx/TiO2, showed instead, a good activity and selectivity towards C-O hydrogenolysis route yielding 37.5% of Butanodiols. Activation energy and reaction orders on ERY (0.58) and H2 (0.53) were estimated from experiences made at different reaction conditions

Easily prepared SiO2–Al2O3-supported Rh and Pd-based catalysts exhibit high activity and selectivity in the pentyl valerate production in liquid phase from γ-valerolactone, pentanol and H2, reaching the highest reported productivity.