Comparative study of Rh–MoOx and Rh–ReOx supported on SiO2 for the hydrogenolysis of ethers and polyols

Rh–MOx/SiO2 (M = Mo or Re) catalysts shows the high activity of the hydrogenolysis of C–O bond in the substrates with CH2OH group such as tetrahydrofurfuryl alcohol, various diols and their ethers. Characterization results suggest the catalyst structure were isolated MoOx species and small ReOx cluster with low valence attached on the surface of Rh metal particles. It is characteristic that the reactivity of the C–O bond in the –O–C–C–CH2OH is higher than that in the –O–C–CH2OH over Rh–MoOx/SiO2, and Rh–ReOx/SiO2 has the opposite tendency to Rh–MoOx/SiO2. The difference in the regioselectivity of the hydrogenolysis over Rh–MoOx/SiO2 and Rh–ReOx/SiO2 can be related to the different structure of isolated MoOx species and small ReOx clusters.

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► Rh-MOx/SiO2 (M = Mo, Re; M/Rh = 0.13) showed high hydrogenolysis activity.
► All the Mo and Re species interacts with Rh metal surface.
► Mo and Re species have isolated and 2-D structure, respectively.
► Different reactivity is due to the difference in the local structure of Mo and Re.