A Low-Noble-Metal Ru@CoMnO Spinel Catalyst for the Efficient Oxidation of Propane.

Noble metals have become a research hotspot for the oxidation of light alkanes due to their low ignition temperature and easy activation of C-H; however, sintering and a high price limit their industrial applications. The preparation of effective and low-noble-metal catalysts still presents profound challenges. Herein, we describe how a Ru@CoMnO spinel catalyst was synthesized via Ru in situ doping to promote the activity of propane oxidation. Ru@CoMnO exhibited much higher catalytic activity than CoMnO, achieving 90% propane conversion at 217 °C. H-TPR, O-TPD, and XPS were used to evaluate the catalyst adsorption/lattice oxygen activity and the adsorption and catalytic oxidation capacity of propane. It could be concluded that Ru promoted synergistic interactions between cobalt and manganese, leading to electron transfer from the highly electronegative Ru to Co and Mn. Compared with CoMnO, 0.1% Ru@CoMnO, with a higher quantity of lattice oxygen and oxygen mobility, possessed a stronger capability of reducibility, which was the main reason for the significant increase in the activity of Ru@CoMnO. In addition, intermediates of the reaction between adsorbed propane and lattice oxygen on the catalyst were monitored by in situ DRIFTS. This work highlights a new strategy for the design of a low-noble-metal catalyst for the efficient oxidation of propane.