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Extensive density-functional theory calculations, and taking into account temperature and pressure, affords a comprehensive picture of the behavior and interaction of oxygen and Ag(111), and provides valuable insight into the function of…

Materials Science · Physics 2009-11-10 Wei-Xue Li , Catherine Stampfl , Matthias Scheffler

To help provide insight into the remarkable catalytic behavior of the oxygen/silver system for heterogeneous oxidation reactions, purely sub-surface oxygen, and structures involving both on-surface and sub-surface oxygen, as well as…

Materials Science · Physics 2009-11-10 Wei-Xue Li , Catherine Stampfl , Matthias Scheffler

In this paper we investigate by means of first-principles density functional theory calculations the (111) surface of the Ag-Cu alloy under varying conditions of pressure of the surrounding oxygen atmosphere and temperature. This alloy has…

Materials Science · Physics 2009-11-13 Simone Piccinin , Catherine Stampfl , Matthias Scheffler

Recent experiments on model catalysts have shown that Ag-Cu alloys have improved selectivity with respect to pure silver for ethylene epoxidation. In this paper we review our first-principles investigations on the (111) surface of this…

Materials Science · Physics 2015-05-13 Simone Piccinin , Catherine Stampfl , Matthias Scheffler

Increasing demand of ethylene oxide and the cost of versatile chemical ethene has been a driving force for understanding mechanism of epoxidation to develop highly selective catalytic process. Direct epoxidation is a proposed mechanism…

Materials Science · Physics 2018-10-17 Nivedita Kenge , Sameer Pitale , Kavita Joshi

Silver chromate ($\mathrm{Ag_{2}CrO_{4}}$) has attracted considerable attention in recent years due to its promising photocatalytic performance, which strongly depends on the crystallographic orientation of its exposed surfaces. A detailed…

Materials Science · Physics 2026-05-20 Augusto Facundes , Thiago T. Dorini , Theodora W. von Zuben , Miguel A. San-Miguel

Copper-based catalysts play a crucial role in industrial oxidation reactions. Although many theoretical studies consider copper to be metallic, it is well established that copper readily oxides at ambient conditions, forming a passivating…

Materials Science · Physics 2025-05-20 E V Charan Reddy , Abhijit Chatterjee

Using density-functional theory we assess the stability of bulk and surface oxides of the late 4d transition metals in a ``constrained equilibrium'' with a gas phase formed of O2 and CO. While the stability range of the most stable bulk…

Materials Science · Physics 2009-11-10 Karsten Reuter , Matthias Scheffler

The possible formation of oxides or thin oxide films (surface oxides) on late transition metal surfaces is recently being recognized as an essential ingredient when aiming to understand catalytic oxidation reactions under technologically…

Materials Science · Physics 2009-11-13 Jutta Rogal , Karsten Reuter , Matthias Scheffler

We use density functional theory calculations to characterize the early stages of fluorination of silver's (100) and (110) surfaces. In the Ag(100) surface, the hollow site is the most favorable for F adatoms. In the Ag(110) surface, three…

The adsorption of oxygen on the Ag(001) is investigated by means of density functional techniques. Starting from a characterization of the clean silver surfaces oxygen adsorption in several modifications (molecularly, on-surface,…

Materials Science · Physics 2009-11-10 M. Gajdos , A. Eichler , J. Hafner

The possible importance of oxide formation for the catalytic activity of transition metals in heterogenous oxidation catalysis has evoked a lively discussion over the recent years. On the more noble transition metals (like Pd, Pt or Ag) the…

Materials Science · Physics 2009-11-13 Jutta Rogal , Karsten Reuter , Matthias Scheffler

Surface oxidation processes are crucial for the functionality of Cu-based catalytic systems used for methanol synthesis, partial oxidation of methanol or the water-gas shift reaction. We assess the stability and population of the…

Materials Science · Physics 2016-01-22 Norina. A. Richter , Chang-Eun Kim , Catherine Stampfl , Aloysius Soon

We employ a multiscale modeling approach to study the surface structure and composition of a Pd(100) model catalyst in reactive environments. Under gas phase conditions representative of technological CO oxidation (~1 atm, 300-600 K) we…

Materials Science · Physics 2007-05-23 Jutta Rogal , Karsten Reuter , Matthias Scheffler

The oxidized Ag(111) surface has been studied by a combination of experimental and theoretical methods, scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). A large variety of…

Pd(111) has recently been shown to exhibit a propensity to form a sub-nanometer thin surface oxide film already well before a full monolayer coverage of adsorbed O atoms is reached on the surface. Aiming at an atomic-scale understanding of…

Materials Science · Physics 2009-11-11 Mira Todorova , Karsten Reuter , Matthias Scheffler

The mobility of O atoms at very low temperatures is not generally taken into account, despite O diffusion would add to a series of processes leading to the observed rich molecular diversity in space. We present a study of the mobility and…

Astrophysics of Galaxies · Physics 2014-02-11 M. Minissale , E. Congiu , F. Dulieu

In recent years due to improvements in calculation methods and increased computer power, it has become possible to perform first-principles investigations for ``simple'' chemical reactions at surfaces. We have carried out such studies for…

Materials Science · Physics 2009-10-31 C. Stampfl , M. Scheffler

Understanding the atomic mechanism of low-temperature CO oxidation on a heterogeneous catalyst is challenging. We performed density functional theory (DFT) calculations to identify the surface structure and reaction mechanism responsible…

Chemical Physics · Physics 2019-05-08 Yongeseon Kim , Hosik Lee , Ja Hun Kwak

The formation of ultrathin oxide layers on metal surfaces is a non-thermally-activated process which takes place spontaneously at very low temperatures within nanoseconds. This paper reports mechanistic details of the initial oxidation of…

Materials Science · Physics 2008-07-23 Lucio Colombi Ciacchi
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