Modifying Ru/C for Selective Hydrodeoxygenation of Carbohydrate‐Rich Streams to Naphtha

ABSTRACT Noble metals on carbon supports are promising catalysts for the hydrodeoxygenation of carbohydrate‐rich waste streams into naphtha‐range alkanes (C 5 ‐C 9 ), key intermediates for fuels and chemicals. Among tested catalysts, Ru/C showed the highest activity due to its oxophilicity but suffered from excessive CC cleavage, lowering C 6 alkane selectivity (39 C%). Pt/C achieved higher C 6 alkane selectivity (56 C%) by suppressing formation of intermediates prone to C‐C scission, though its high cost limits scalability. To improve Ru/C performance, hydrothermal pretreatments with and without H 4 SiW 12 O 40 in solution were applied, boosting C 6 alkane yield to 56 C% and C 5 ‐C 6 alkane yield to 66 C%, surpassing Pt/C catalysis. Ru dispersion remained intact at short residence times during pretreatment without H 4 SiW 12 O 40 , while surface acidity was reduced, hindering C─O cleavage. The addition of H 4 SiW 12 O 40 during pretreatment restored acidity, incorporating reduced WOx species in the catalyst pores. However, excessive acid incorporation led to pore blockage and Ru oxidation to a less active RuO 2 phase. These findings emphasize the need to carefully balance acidity, metal oxidation state, particle size, and support porosity to optimize naphtha production from renewable carbohydrates.