Chemoselective Hydrogenolysis of Tetrahydropyran-2-methanol to 1,6-Hexanediol over Rhenium-Modified Carbon-Supported Rhodium Catalysts

Modification of Rh/C with Re species enabled chemoselective hydrogenolysis of tetrahydropyran‐2‐methanol to 1,6‐hexanediol. In particular, the Rh–ReOx/C (Re/Rh ratio=0.25) catalyst gave a high yield of 1,6‐hexanediol (84 %) and showed a very low activity for overhydrogenolysis to 1‐hexanol. Using the same catalyst in the hydrogenolysis of tetrahydrofurfuryl alcohol also gave a high yield of 1,5‐pentanediol (94 %). Characterization results indicate the formation of ReOx clusters attached on the surface of Rh metal particles. This can cause the synergy between ReOx and Rh, and the tetrahydropyran‐2‐methanol hydrogenolysis proceeds on the interface between Rh metal surface and attached ReOx species. Modify M for diols: The industrially important monomer 1,6‐hexanediol can be produced from hydrogenolysis of tetrahydropyran‐2‐ methanol, which can be derived from acrolein or glycerol, using Re‐modified Rh/C as a heterogeneous catalyst. Conventional catalysts such as M/C (M=Rh, Ru, Pd, or Pt), copper chromite and Raney nickel show poor activity and selectivity for this reaction.