Organometallic compound as an efficient catalyst toward oxygen reduction reaction

Abstract

The interaction between oxygen molecule (O2) and organometallic compounds has always been an interesting research topic because O2 plays a benchmark role for demonstrating activity level of the organometallic-based catalysts. In this work, the effect of various transition metals (TMs) on the interaction between O2 and TM-CmHm organometallic compounds is investigated using density functional theory (DFT) calculations. Our results show that the TM decoration enhances the reactivity of CmHm, however, it is more effective in the case of Sc-decorated on the CmHm systems. In addition, the O2 adsorption energy and OO bond length activation are considerably changed with changing the TM atoms in the TM-CmHm organometallics compounds. Consistent with the prediction of chemical hardness descriptors, the best catalytic activity toward O2 activation is related to the Sc-decorated on CmHm systems. The Sc-CmHm organometallic compounds strengthen the interaction between O2 and Sc atom, resulting in increased adsorption energy; the corresponding OO bond length is also elongated. Moreover, the energy barrier of the O2 activation on the Sc-C6H6 is less than 0.50 eV, representing that the reaction can proceed easily at room temperature. Because the bond length of the O2 correlates with its catalytic activation, the results can provide a new application of organometallic-based catalysts.