Promotional Role of Surface Defects on Carbon‐Supported Ruthenium‐Based Catalysts in the Transfer Hydrogenation of Furfural

The synthesis of highly efficient supported metal catalysts is of vital importance for the modern development of the production of chemicals. In this regard, biomass-based chemical transformation holds potential promise through many heterogeneous catalytic processes. Herein, we report surface defect engineering on carbon-supported Ru-based catalyst via a two-step hybridization-self reduction route, which involves the assembly of hybrid composite of ternary Co-Al-Ru layered double hydroxide (CoAlRu-LDH) and amorphous carbon through the carbonization of glucose and following an in situ self-reduction process. The results revealed that Ru3+ species in the resulting CoAlRu-LDH-C composite could be in situ reduced to Ru0 species by the carbon component in the hybrid composite, and Co-containing spinels with a large quantity of surface oxygen vacancies could be simultaneously formed on the surface. As-fabricated Ru-based catalyst was found to show a superior catalytic performance in the liquid phase transfer hydrogenation of furfural to furfuryl alcohol using benzyl alcohol as hydrogen donator to other Ru-based ones derived from LDH-C composite precursors. It was proven that surface defects (i.e. oxygen vacancies, Co2+ species) could enable spatially the chemisorption of furfural and ensure the activation of carbonyl groups in furfural, thereby greatly promoting the transfer hydrogenation.