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.
Latine et al. (Thu,) studied this question.