Transfer Hydrogenation of Vanillin with Formic Acid over Graphene-Encapsulated Nitrogen-Doped Bimetallic Magnetic Pd/Fe@N/C Catalyst

The improved biomass-derived aldehyde compounds represent a valuable route to the production of high-value-added fuels and chemicals. However, the majority of mature catalytic systems exhibit low hydrodeoxygenation (HDO) activity, even under harsh reaction conditions. In this study, it was observed that a Pd/Fe magnetic bimetallic catalyst, in conjunction with formic acid (FA) as a hydrogen source and nitrogen-containing carbon material as a support, exhibited remarkable catalytic performance for the conversion of phenyl aldehydes in oxygenates derived from crude lignin. In the hydrogenation of vanillin, the Pd/Fe@N/C catalyst demonstrated superior catalytic activity under mild reaction conditions of 80 °C. When ethyl acetate was used as the solvent, the product was vanillyl alcohol (VA), and when cyclohexane was employed as the solvent, the product was p-methyl guaiacol (MMP). The yields achieved were 84.5% and 92.3%, respectively. It is recommended that further exploration of the FLOW reactor system be considered at a later stage due to the magnetic and easily separable characteristics of the catalyst. The excellent mass transfer and heat transfer performance of the FLOW reactor system will further ensure that the reaction conditions are moderate and will strive to achieve normal-temperature conversion.