Pd-Cu/SiO2 catalyzed efficient hydrogen transfer of cyclohexanol and furfural platforms into cyclohexanone and furfuryl alcohol

High-performance and cost-effective designing of bimetallic catalysts is crucial for the efficient biomass-derived cyclic platforms conversion into fuel additives. To improve the hydrogen transfer efficiency between cyclohexanol and furfural, a Pd-Cu/SiO2 composite with self-synthesized mesoporous SiO2 support was developed and characterized. The state of Pd-Cu metal and catalyst surface were investigated through XRD, TEM, XPS, IR, H-2-TPR and NH3-TPD. The transfer hydrogenation of furfural into furfuryl alcohol through cyclohexanol dehydrogenation in the liquid phase was investigated and completed in hydrogen acceptor to donor molar ratios of 1:6-1:1.5, with significantly improved furfural hydrogenation capacity, achieving 84.6 % of furfuryl alcohol species molar yield with 97.7 % selectivity at 195 degrees C, 10 h, in 1:3 M ratio. The reaction was promoted in a molar ratio of 1:1 unprecedentedly without hydrogen wasted, and the reactant and product platforms were further investigated for the condensation synthesis of C-11 fuel additives. Reaction mechanism was investigated using 1,4-cyclohexanediol as model reactant at 240 and 280 degrees C, confirming the high selectivity of products originated from the non-planar adsorption state of reactant on the metal catalyst. This simple and active Pd-Cu bimetallic catalytic system may offer a cutting-edge liquid biofuel production pathway with potential industrial application due to its excellent stability and reproducibility.