title: Establishing and Understanding Adsorption-Energy Scaling Relations with Negative Slopes.
abstract: Adsorption-energy scaling relations are widely used for the design of catalytic materials. To date, only linear scaling relations are known in which the slopes are positive. Considering the adsorption energies of F, O, N, C, and B on transition metals, we show here that scaling relations with negative slopes also exist between certain adsorbates. The origin of such unconventional scaling relations is analyzed in terms of common descriptors such as d-band center, work function, number of outer electrons, electronic charge on the adsorbates, integrated crystal orbital overlap populations, and crystal orbital Hamilton populations. Conventional scaling relations are formed between adsorbates such as F, O, N, and C, which create ionic-like bonds with surfaces. Conversely, anomalous scaling relations are established between those and covalently bound adsorbates such as B. This widens the theory of adsorption-energy scaling relations and opens new avenues in physical chemistry and catalysis, for instance, in direct borohydride fuel cells.
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Science , Dalian 116023, China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Su
authors.affiliation: Key Laboratory of Applied Chemistry, College of Environmental and Chemical Engineering, Yanshan University , Qinhuangdao 066004, China.
authors.forename: Keju
authors.initials: K
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Science , Dalian 116023, China.
authors.forename: Wei-Qi
authors.initials: WQ
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Science , Dalian 116023, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: Leiden Institute of Chemistry, Leiden University , Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Federico
authors.identifier: http://orcid.org/0000-0001-5147-8635
authors.initials: F
authors.lastname: Calle-Vallejo
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Science , Dalian 116023, China.|College of Chemistry and Material Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, iChEM, CAS Center for Excellence in Nanoscience, University of Science and Technology of China , Hefei 230026, China.
authors.forename: Wei-Xue
authors.identifier: http://orcid.org/0000-0002-5043-3088
authors.initials: WX
authors.lastname: Li