γ-Valerolactone (GVL) has been identified as a sustainable platform chemical for the production of carbon-based chemicals. We here report an experimental study on the catalytic hydrogenation of levulinic acid (LA) in water to GVL in a packed bed reactor using supported Ru catalysts (carbon, alumina, and titania) with particle sizes in the millimeter range (C LA,0 = 1.2 mol/L, LA feed = 1 mL/min, H 2 feed = 30 mL/min, 90 °C, 45 bar, and WHSV = 30 g feed /g cat •h). Intraparticle diffusion limitations for hydrogen and LA were confirmed by performing LA hydrogenation experiments with different catalyst particle sizes (0.5 wt % Ru/C) and supported by calculations. The best performance was obtained with Ru/C, showing high LA conversion during 6 h on stream with negligible deactivation. Ru/Al 2 O 3 was found to be less active, and stability was also considerably reduced due to the reactivity of the support. Ru/TiO 2 was considerably less reactive, though stability was better than that for the alumina based counterpart. A long duration test (52 h) for Ru/C (0.5 wt % of Ru) showed a small though significant reduction in LA conversion (from 95 to 82 mol %). Catalyst characterization studies showed a significant decrease in the specific surface area of the catalyst (from 1110 m 2 /g to 390 m 2 /g) and sintering of the Ru particles (TEM-HAADF).

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γ-Valerolactone (GVL) has been identified as a sustainable platform chemical for the production of carbon-based chemicals. Here we report a screening study on the hydrogenation of levulinic acid (LA) to GVL in water using a wide range of ruthenium supported catalysts in a batch set-up (1 wt. % Ru, 90 • C, 45 bar of H 2 , 2 wt. % catalyst on LA). Eight monometallic catalysts were tested on carbon based(C, carbon nanotubes (CNT)) and inorganic supports (Al 2 O 3 , SiO 2 , TiO 2 , ZrO 2 , Nb 2 O 5 and Beta-12.5). The best result was found for Ru/Beta-12.5 with almost quantitative LA conversion (94%) and 66% of GVL yield after 2 h reaction. The remaining product was 4-hydroxypentanoic acid (4-HPA). Catalytic activity for a bimetallic RuPd/TiO 2 catalyst was by far lower than for the monometallic Ru catalyst (9% conversion after 2 h). The effects of relevant catalyst properties (average Ru nanoparticle size, Brunauer-Emmett-Teller (BET) surface area, micropore area and total acidity) on catalyst activity were assessed.