title: Identification of Surface Reactivity Descriptor for Transition Metal Oxides in Oxygen Evolution Reaction.
abstract: A number of important reactions such as the oxygen evolution reaction (OER) are catalyzed by transition metal oxides (TMOs), the surface reactivity of which is rather elusive. Therefore, rationally tailoring adsorption energy of intermediates on TMOs to achieve desirable catalytic performance still remains a great challenge. Here we show the identification of a general and tunable surface structure, coordinatively unsaturated metal cation (MCUS), as a good surface reactivity descriptor for TMOs in OER. Surface reactivity of a given TMO increases monotonically with the density of MCUS, and thus the increase in MCUS improves the catalytic activity for weak-binding TMOs but impairs that for strong-binding ones. The electronic origin of the surface reactivity can be well explained by a new model proposed in this work, wherein the energy of the highest-occupied d-states relative to the Fermi level determines the intermediates' bonding strength by affecting the filling of the antibonding states. Our model for the first time well describes the reactivity trends among TMOs, and would initiate viable design principles for, but not limited to, OER catalysts.
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive, Singapore 637459, Singapore.
authors.forename: Hua Bing
authors.initials: HB
authors.lastname: Tao
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University , Wuhan 430072, PR China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Fang
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive, Singapore 637459, Singapore.
authors.forename: Jiazang
authors.initials: J
authors.lastname: Chen
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive, Singapore 637459, Singapore.
authors.forename: Hong Bin
authors.initials: HB
authors.lastname: Yang
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive, Singapore 637459, Singapore.
authors.forename: Jiajian
authors.initials: J
authors.lastname: Gao
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive, Singapore 637459, Singapore.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Miao
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University , Wuhan 430072, PR China.
authors.forename: Shengli
authors.initials: S
authors.lastname: Chen
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive, Singapore 637459, Singapore.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu