Theoretical Investigations of the Oxygen Reduction Reaction on Pt(111)

Abstract

Computational modeling can provide important insights into chemical reactions in both applied and fundamental fields of research. One of the most critical processes needed in practical renewable energy sources is the oxygen reduction reaction (ORR). Besides being the key process in combustion and corrosion, the ORR has an elusive mechanism that may proceed in a number of complicated reaction steps in electrochemical fuel cells. Indeed, the mechanism of the ORR on highly studied Pt(111) electrodes has been the subject of interest and debate for decades. Herein, we first outline the theory behind these types of simulations and then show how to use these quantum mechanical approaches and approximations to create a realistic model. After reviewing the performance of these methods in studying the binding of molecular oxygen to Pt(111), we then outline our own results in elucidating the ORR and its dependence on environmental parameters, such as solvent, thermodynamic energies, and the presence of an external electrode potential. This approach can, in principle, be applied to other equally complicated investigations of other surfaces or electrochemical reactions.

Theoretical Studies of Potential‐Dependent and Competing Mechanisms of the Electrocatalytic Oxygen Reduction Reaction on Pt(111)

“…[4] Herein, we used a Pt 35 cluster as a basis for first-principles density functional theory (DFT) calculations on the electrocatalytic ORR on Pt(111). Calculations were run at the B3LYP/LACVP** level as calculated by the Jaguar program.…”

Microkinetic Modeling of the Oxygen Reduction Reaction at the Pt(111)/Gas Interface

“…The activation energies, zero-point-energy (ZPE) corrections and Gibbs free energies are presented in Table 1 and were taken from Refs. [18,19,25]. These activation energies were used to compute temperaturedependent reaction rate constants for each reaction within the context of transition state theory.…”

“…Furthermore, DFT calculations can be used to predict the properties of molecules and materials in the rational design of catalysts [16]. Along these lines, DFT calculations have been utilized to investigate the mechanistic details of the ORR on Pt(111) [17][18][19]. Three different pathways were distinguished: the O 2 dissociation mechanism, the OOH dissociation mechanism and the H 2 O 2 dissociation mechanism.…”

Oxygen reduction on a Pt(111) catalyst in HT-PEM fuel cells by density functional theory

“…Pt(111) surface is the most active compared to other surface. 34,35 Then, the Pt(111) surface was cut from the optimized Pt primitive cell. 41 To develop a super cell as a geometric model system, four layers of Pt atoms were placed in this system; the lowest two layers were restrained on the bottom of this system, and a vacuum thickness of 2.0 nm was set up above the Pt atoms (Fig.…”

“…31 Because the catalytic activity of the Pt(111) surface is higher than that of other Pt surfaces, 32,33 the Pt(111) surface is considered to be the one that most readily adsorbs the oxygen molecule. 34,35 First-principle mechanism and its density functional theory are often used in the electrochemical modeling of the oxygen reduction reaction on Pt(111). [36][37][38] In a previous study that used the density functional theory method, the electric field and solvent were considered as factors that influence the oxygen reduction reaction on Pt(111).…”