Effects of TiO structure and Co addition as a second metal on Ru-based catalysts supported on TiO for selective hydrogenation of furfural to FA.

The TiO supported Ru-based catalysts were prepared with 1.5 wt% Ru and 0-0.8 wt% Co on various TiO (anatase, rutile, P-25, and sol-gel TiO) and studied in the liquid-phase selective hydrogenation of furfural to furfuryl alcohol (FA) under mild conditions (50 °C and 2 MPa H). The presence of high anatase crystallographic composition on TiO support was favorable for enhancing hydrogenation activity, while the strong interaction between Ru and TiO (Ru-TiO sites) was required for promoting the selectivity to FA. The catalytic performances of bimetallic Ru-Co catalysts were improved with increasing Co loading due to the synergistic effect of Ru-Co alloying system together with the strong interaction between Ru and Co as revealed by XPS, H-TPR, and TEM-EDX results. The enhancement of reducibility of Co oxides in the bimetallic Ru-Co catalysts led to higher hydrogenation activity with the Ru-0.6Co/TiO catalyst exhibited the best performances in FA selective hydrogenation of furfural to FA under the reaction conditions used.