Insights into Catalytic Oxidative Reaction Mechanisms of Pentane on the Ru(0001) Surface.

Developing efficient and selective oxidative transformations of light alkanes into alkenes or oxygenates is vital for advancing to cleaner and more efficient chemical processes. A suitable selective catalyst is required to ease reaction conditions and ensure the formation of desired oxygenated compounds. Here, using periodic density functional theory, we have investigated the suitability of a ruthenium catalyst for the partial oxidation of n-pentane using molecular oxygen. The first step of the process involves the dehydrogenation of primary or secondary carbons in the aliphatic chain, resulting in an adsorbed hydride structure on the metal surface. The intermediate may proceed through different reaction pathways, leading to various products. The successive dehydrogenation, a faster process than the first oxidative dehydrogenation, produces pentene and a water molecule. Alternatively, the direct interaction of the hydroxyl group with the pentyl hydride produces alcohol. The atomistic simulations reveal that Ru is a suitable candidate for catalyzing the conversion of alkanes into alkenes and oxygenates. As a significant outcome, we have observed that catalytic oxidative dehydrogenation is more feasible than direct catalytic dehydrogenation for yielding olefins from alkanes.