Adsorption and activation of CO2 on Pt/CeOx/TiO2(110): Role of the Pt-CeOx interface

SURFACE SCIENCE

卷:710

Article

Grinter, David C.^1,2  Graciani, Jesus³  Palomino, Robert M.¹  Xu, Fang^1,4  Waluyo, Iradwikanari⁵  Sanz, Javier Fdez³  Senanayake, Sanjaya D.¹  Rodriguez, Jose A.^1,4 

[1] Brookhaven Natl Lab, Chem Div, Upton, NY 11973 USA

[2] Diamond Light Source, Didcot OX11 0DE, Oxon, England

[3] Univ Seville, Dept Quim Fis, Seville 41012, Spain

[4] Univ Texas San Antonio, Dept Chem, San Antonio, TX 78249 USA

[5] Brookhaven Natl Lab, Natl Synchrotron Light Source 2, Upton, NY 11973 USA

关键词: Carbon dioxide;    Platinum;    Ceria;    Titania;    Ambient-pressure x-ray photoelectron spectroscopy;    Density functional calculations;   

DOI  :  10.1016/j.susc.2021.121852

来源: Elsevier

【 摘 要 】

The adsorption and dissociation of CO2 on TiO2(110), CeOx/TiO2(110) and Pt/CeOx/TiO2(110) surfaces has been examined using Ambient Pressure X-ray Photoelectron Spectroscopy (AP-XPS). The substrates under study exhibited different degrees of complexity which were tested for the binding of the adsorbate and the cleavage of C-O bonds. The surfaces were prepared by depositing CeOx (0.1 ML) onto TiO2(110) to form a mixed oxide support, onto which Pt nanoparticles (0.2 ML) were deposited. This configuration yields a complex set of interfaces between metal and oxides and we have systematically titrated the active role of each component (Pt 4f, Ce 3d and Ti 2p regions) and the arising surface intermediates (C 1 s and O 1 s regions). CO2 barely bonds to stoichiometric TiO2(110). It heals oxygen vacancies of this oxide surface (CO2,gas -> COgas + O-a) and does not form stable carbonates. A stable carbonate was seen upon adsorption of CO2 on CeOx/TiO2(110) and on this type of substrate the adsorbate also removed O vacancies leading to the oxidation of Ti(3+)and Ce3+ sites. Pt nanoparticles dispersed on CeOx/TiO2(110) were highly effective for the binding and dissociation of CO2, with the formation of CO3, CO, C and CHx species on the Pt/CeOx/TiO2(110) system. The results of theoretical calculations based on density-functional theory (DFT) show that Pt/CeOx/TiO2(110) binds CO2 much stronger than surfaces of bulk platinum {(111), (100), (110)} or other late transition metals. On a Pt-CeOx interface, the molecule adsorbs with a bent configuration (similar to 130 degrees O-C-O bond angle) and with a substantial elongation (similar to 0.1 angstrom) of the C-O bonds, facilitating its transformation into high value chemicals.

【 授权许可】

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