Direct Hydrogenation of Furfural to 2-Methyltetrahydrofuran over an Efficient Cu–Pd/HY Bimetallic Catalyst

The direct one-pot conversion of furfural to 2-methyltetrahydrofuran (2-MTHF) was investigated in liquid phases using H2 as a hydrogen source over a bimetallic Cu–Pd/HY catalyst. This catalyst showed excellent catalytic reactivity toward the formation of 2-MTHF with a yield of 83.1% under optimized reaction conditions. By adjusting the Cu/Pd ratio in the catalyst, the desired product could be obtained selectively. This was due to (1) selective catalysis of Cu toward C=O bonds in furfural, (2) excellent hydrogenation ability of Pd, and (3) the synergistic effects between Cu, Pd, and the acidic sites of the support HY. The influences of other parameters on conversion and selectivity were also investigated. Mechanism studies revealed that reactions mainly perform through the hydrogenation of furfural to furfuryl alcohol and then hydrodeoxygenation to 2-methylfuran followed by furan ring hydrogenation to 2-MTHF. Finally, after five recycling runs, this catalyst still displayed high catalytic behavior and stability, which provided a certain foundation for future research of furfural catalytic hydrogenation to 2-MTHF.