Photocatalytic Selective Hydrogenation of Furfural to Furfuryl Alcohol over Titanium(IV) Oxide

Photocatalytic hydrogenation of furfural (FAL) was examined in 2-pentanol suspensions of TiO2 under metal-free and hydrogen-free conditions. High chemoselectivity was observed, i.e., only the carbonyl group of FAL was reduced to a hydroxymethyl group, resulting in almost quantitative conversion to furfuryl alcohol (FOL) with an apparent quantum efficiency of 17%. 2-Pentanol was simultaneously converted to 2-pentanone satisfying a high stoichiometry with FAL to FOL, indicating that double up-grading of FAL and alcohol was possible via a photocatalytic process.