Highly Efficient Deoxydehydration and Hydrodeoxygenation on MoS2‑Supported Transition-Metal Atoms through a C–H Activation Mechanism

Deoxydehydration (DODH) is an efficient process for the removal of vicinal OH groups of a diol or polyol. Conventional DODH reactions usually take place at a single-site MOx (M = Re, Mo, V, etc.) active center, which proceed through a diol condensation step, an alkene extrusion step, and a catalyst regeneration (or reduction) step. Here, we suggest that MoS2-supported transition-metal atoms allow for the DODH reaction to occur through an alternative mechanism, whereby the C–H bond of a diol is activated first, which facilitates the C–OH bond cleavage on a neighboring carbon. The removal of the second OH group is also facile over the proposed catalysts. Our kinetic studies suggest that the DODH of ethylene glycol on Ru2/MoS2, Ir2/MoS2, and Ru3/MoS2 is highly active with predicted turnover frequencies of over 1/s. Thus, our study suggests a possible approach for the design of highly active DODH catalysts. Apart from being a DODH catalyst, the proposed MoS2-supported catalysts are also highly active as the hydrodeoxygenation catalyst for the removal of alcohol OH groups.