New Bonding Model of Radical Adsorbate on Lattice Oxygen of Perovskites
Victor Funga, Zili Wub, De‐en Jianga✉
- aDepartment of Chemistry, University of California, Riverside, California 92521, United States
- bChemical Sciences Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- ✉Corresponding author
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Abstract
A new model of bonding between radical adsorbates and lattice oxygens is proposed that considers both the adsorbate–oxygen bonding and the weakening of the metal–oxygen bonds. Density functional calculations of SrMO 3 perovskites for M being 3d, 4d, and 5d transition metals are used to correlate the bulk electronic structure with the surface-oxygen reactivity. Occupation of the metal–oxygen antibonding states, examined via the crystal orbital Hamilton population (COHP), is found to be a useful bulk descriptor that correlates with the vacancy formation energy of the lattice oxygen and its hydrogen adsorption energy. Analysis of density-of-states and COHP indicates that H adsorption energy is a combined result of formation of the O–H bond and the weakening of the surface metal–oxygen bond due to occupation of the metal–oxygen antibonding states by the electron from H. This insight will be useful in understanding the trends in surface reactivity of perovskites and transition-metal oxides in general.
TL;DRAnalysis of density-of-states and COHP indicates that H adsorption energy is a combined result of formation of the O-H bond and the weakening of the surface metal-oxygen bond due to occupation of the metal- oxygengen antibonding states by the electron from H. (Semantic Scholar)