Chemoselective hydrogenolysis of tetrahydrofurfuryl alcohol to 1,5-pentanediol over Ir-MoOx/SiO2 catalyst

In this work, MoO_x promoted Ir/SiO₂ catalysts were prepared and used for the selective hydrogenolysis of tetrahydrofurfuryl alcohol (THFA) to 1,5-pentanediol in a continuous flow reactor. The effects of different noble metals (Ir, Pt, Pd, Ru, Rh), supports and Ir contents were screened. Among the investigated catalysts, 4 wt%Ir-MoO_x/SiO₂ with a Mo/Ir atomic ratio of 0.13 exhibited the best catalytic performance. The synergy between Ir particles and the partially reduced isolated MoO_x species attached on them is essential for the excellent catalytic performance of Ir-MoO_x/SiO₂. The catalyst exhibited a better hydrogenolysis efficiency of THFA with the selectivity of 1,5-pentanediol of 65%–74% at a conversion of THFA of 70%–75% when the initial THFA concentration is ranging from 20 wt% and 40 wt%. And higher system pressure was also in favor of the conversion of THFA. During a stability test, the conversion of THFA and 1,5-pentanediol yield over Ir-MoO_x/SiO₂ decreased with reaction time, which can be explained by the leaching of Mo species during the reaction.