A comprehensive study of palladium-based catalysts on different supports for the hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) biofuel

Hydrogenation and hydrogenolysis are the two essential processes which have massive importance on the industrial level to produce value-added chemicals. The hydrogenation or hydrogenolysis of 5-HMF; a key furan compound obtained from the cellulosic biomass led to the formation of 2,5-dimethylfuran (DMF), which is considered as a future biofuel globally because of its high energy density (32.8 MJ/L), water immiscibility and high boiling point (96 °C). The palladium-based catalysts are the most crucial catalysts used in industries for various chemical transformations specifically in hydrogenation reactions. In this review article, we examined the general progress of palladium catalysts on various supports including charcoal, metal organic framework, metal oxides, graphene oxides, acidic supports and critically assessed how the influence of various supports controls the conversion of 5-HMF to DMF. Moreover, the present research's limitations and flaws are also discussed. In the concluding section, we explore the unique catalytic properties necessary for achieving the desired conversion, which aids researchers in developing a suitable catalyst. Overall, palladium catalysis is still in great shape and will require a critical look in the future.