Growth of Stable Surface Oxides on Pt(111) at Near‐Ambient Pressures. Issue 10 (25th January 2017)

• Record Type: Journal Article
• Authors: Fantauzzi, Donato; Krick Calderón, Sandra; Mueller, Jonathan E.; Grabau, Mathias; Papp, Christian; Steinrück, Hans‐Peter; Senftle, Thomas P.; van Duin, Adri C. T.; Jacob, Timo
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 10(2017)
• Page Start: 2594
• Page End: 2598
• Publication Date: 2017-01-25
• Subjects: interfaces -- kinetics -- oxidation -- phase transitions -- surface chemistry; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201609317
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Detailed knowledge of the structure and degree of oxidation of platinum surfaces under operando conditions is essential for understanding catalytic performance. However, experimental investigations of platinum surface oxides have been hampered by technical limitations, preventing in situ investigations at relevant pressures. As a result, the time‐dependent evolution of oxide formation has only received superficial treatment. In addition, the amorphous structures of many surface oxides have hindered realistic theoretical studies. Using near‐ambient pressure X‐ray photoelectron spectroscopy (NAP‐XPS) we show that a time scale of hours ( t ≥4 h) is required for the formation of platinum surface oxides. These experimental observations are consistent with ReaxFF grand canonical Monte Carlo (ReaxFF‐GCMC) calculations, predicting the structures and coverages of stable, amorphous surface oxides at temperatures between 430–680 K and an O2 partial pressure of 1 mbar. Abstract : Stable surface oxides : Stable surface oxides on Pt(111) at near‐ambient pressure were theoretically predicted and their existence was confirmed by X‐ray photoelectron spectroscopy. The presence of these stable surface oxides has severe implications for Pt catalysts, since their catalytic properties differ markedly from those of bare Pt surfaces.