Mechanisms of the Water–Gas Shift Reaction Catalyzed by Carbonyl Complexes Mo(CO)6 and Mo2(CO)10: A Density Functional Theory Study

Four different mechanistic pathways for Mo(CO)6 and a reaction mechanism for the binuclear species Mo2(CO)10 catalyzed water–gas shift reaction (WGSR) have been analyzed using density functional method. It turned out that the binuclear catalyst provides more facile transformations through lower barriers in comparison to the mononuclear catalyst, which is explained by the metal–metal cooperativity between the two Mo centers. The energy span model indicates that the higher the TOF calculated, the faster the catalytic rate and the higher the catalytic efficiency. The bimetallic catalyst (Mo2(CO)10) with the highest value of the calculated TOF (2.60 × 10−15 s−1), which is higher than that of Fe2(CO)9 (8.96 × 10−20 s−1) (see Kuriakose et al. in Inorg Chem 51: 377, 2012). The later prove the WGSR catalyst with high performance. Our conclusions will be useful for the design of improved WGSR catalysts in the future.