Dissociative Adsorption of O₂ on Al(111): The Role of Orientational Degrees of Freedom

Abstract

The interaction between O2 molecules and Al surfaces has long been poorly understood despite its importance in diverse chemical phenomena. Early experimental investigations of adsorption dynamics indicated that abstraction of a single O atom by the surface, instead of dissociative chemisorption, dominates at low O2 incident kinetic energies. Abstraction of the closer O atom suggests low barrier heights at perpendicular incidence. However, recent measurements suggest that parallel O2 orientations dominate sticking at low energies. We resolve this apparent contradiction by a systematic ab initio embedded correlated wavefunction study of the stereochemistry of O2 reacting with Al(111). We identify two important new details: (i) initially, roughly parallel oxygen molecules tend to tilt upright while approaching the surface, suggesting that the abstraction channel does dominate at low energies and (ii) the reaction channel with the lowest barrier indeed corresponds to a parallel orientation, which ultimately evolves either into dissociative chemisorption or toward abstraction.

Dissociative Chemisorption of O2 on Al(111): Dynamics on a Correlated Wave-Function-Based Potential Energy Surface

“…The ECW total energy thus is expressed as To construct the PES, we collect over 700 single points above three high-symmetry sites: top, bridge, and fcc. These data were mainly used to generate the two-dimensional (2D) cuts reported in refs ( 27 ) and ( 31 ) with the O 2 molecule lying either parallel or perpendicular to the surface. Because of the limited number of data points, we took advantage of the physically inspired flexible periodic London–Eyring–Polanyi–Sato (FPLEPS) function 34 , 35 to represent the 6D PES.…”

A DFT study of O2 and Cl2 adsorption onto Al12N12 fullerene‐like nanocluster

“…Adsorption of Cl 2 and O 2 molecules onto different surfaces has been studied for different times . The interaction of oxygen on metal and metal‐like surfaces is important in different viewpoints, for example, heterogeneous catalysts and surface corrosions .…”

“…The interaction of oxygen on metal and metal‐like surfaces is important in different viewpoints, for example, heterogeneous catalysts and surface corrosions . For this reason, there are many interests to introduce a new surface for O 2 adsorbent/sensor in literature …”

“…Adsorption of Cl 2 and O 2 molecules onto different surfaces has been studied for different times. [1][2][3][4][5][6][7][8] The interaction of oxygen on metal and metal-like surfaces is important in different viewpoints, for example, heterogeneous catalysts and surface corrosions. [1] For this reason, there are many interests to introduce a new surface for O 2 adsorbent/sensor in literature.…”

“…[1] For this reason, there are many interests to introduce a new surface for O 2 adsorbent/sensor in literature. [2][3][4] Moreover, since the early 1980s, Cl 2 interaction onto different surfaces has enthralled many experimental and theoretical works. [5][6][7][8] There are different articles in literature focusing on the adsorption property of Cl 2 , including semiconductors [5][6][7] and metals.…”