Trends in C-O and N-O bond scission on rutile oxides described using oxygen vacancy formation energies

Hai-Yan Su; Xiufang Ma; Keju Sun; Chenghua Sun; Yongjun Xu; Federico Calle-Vallejo

doi:10.1039/d0sc00534g

Trends in C-O and N-O bond scission on rutile oxides described using oxygen vacancy formation energies

Chem Sci. 2020 Mar 23;11(16):4119-4124. doi: 10.1039/d0sc00534g.

Authors

Hai-Yan Su^{1

2}, Xiufang Ma³, Keju Sun⁴, Chenghua Sun^{1

5}, Yongjun Xu¹, Federico Calle-Vallejo⁶

Affiliations

¹ School of Chemical Engineering and Energy Technology, Dongguan University of Technology Dongguan 523808 China.
² State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Science Dalian 116023 China.
³ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Optoelectronic Engineering, Shenzhen University Shenzhen 518060 China.
⁴ Key Laboratory of Applied Chemistry, College of Environmental and Chemical Engineering, Yanshan University 438 Hebei Avenue Qinhuangdao 066004 China kjsun@ysu.edu.cn.
⁵ Centre for Translational Atomaterials, Swinburne University of Technology Hawthorn Victoria 3122 Australia.
⁶ Departament de Ciència de Materials i Química Física, Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona Martí i Franquès 1 08028 Barcelona Spain f.calle.vallejo@ub.edu.

Abstract

Reactivity trends on transition metals can generally be understood through the d-band model, but no analogous theory exists for transition metal oxides. This limits the generality of analyses in oxide-based catalysis and surface chemistry and has motivated the appearance of numerous descriptors. Here we show that oxygen vacancy formation energy (ΔE _Vac) is an inexpensive yet accurate and general descriptor for trends in transition-state energies, which are usually difficult to assess. For rutile-type oxides (MO₂ with M = 3d metals from Ti to Ni), we show that ΔE _Vac captures the trends in C-O and N-O bond scission of CO₂, CH₃OH, N₂O, and NH₂OH at oxygen vacancies. The proportionality between ΔE _Vac and transition-state energies is rationalized by analyzing the oxygen-metal bonds, which change from ionic to covalent from TiO₂ to NiO₂. ΔE _Vac may be used to design oxide catalysts, in particular those where lattice oxygen and/or oxygen vacancies participate in the catalytic cycles.