Alkyl C–O bond cleavage assisted by partial C–H activation on atomically dispersed catalysts and metal surfaces

Summary

We demonstrate a mechanism that achieves alkyl C–O bond cleavage on transition metal (TM) catalysts by overcoming a transition state involving a partially activated C–H bond and an O–TM bond. C–H binds with TMs through α-agostic or agostic-like interactions, hence the notable elongation of the C–H bond length. Upon the cleavage of the C–O bond, the C–H bond is restored. Using tetrahydrofurfuryl alcohol (THFA) as a probe molecule, we were able to regulate the selectivity of THFA ring opening by tuning the oxophilicity of TMs for MoS₂-supported dual-metal catalysts, which in turn affected the reaction mechanism of C–O bond cleavage, being either the partial C–H-activation-assisted or the oxygen-bonded mechanism. We validated the partial C–H-activation-assisted mechanism for the C–O bond cleavage of methanol on dual-metal catalysts, on the basis of which we established that the transition-state energy is contributed by the C–H/TM and O/TM interactions.