Insights into the route of 5-hydroxymethylfurfural hydrodeoxygenation to 2,5-dimethylfuran over N-doped carbon anchored CoMo bimetallic catalyst

5-Hydroxymethylfurfural (HMF) hydrodeoxygenation to 2,5-dimethylfuran (DMF) plays a significant role in biomass conversion. Herein, we develop a facile CoMo bimetallic catalyst with CoN4 single atom sites and low Co content (0.14 wt%) for this transformation which exhibits superior performance than most previous works (Turnover frequency up to 28.7 h−1, more than 8 cycles). A synergistic catalytic effect between Co and Mo sites are disclosed, in which the Mo sites mainly take part in the adsorption of substrates, while the Co sites mainly realize the adsorption and activation of H2. The mechanistic studies demonstrate that 5-methyl-2-furaldehyde (MF) is the main reason for the production of 1,2-bis(5-methylfuran-2-yl)ethane (BMF), and the hydrogenolysis of the aldehyde group is the slow step of this reaction. According to these insights into the mechanism, a two-step and one-pot process is firstly exploited for the HMF hydrodeoxygenation, resulting in a higher DMF yield under milder conditions.