How low can you go? Minimum energy pathways for O2 dissociation on Pt(111)

Abstract

Many DFT studies of O(2) dissociation on Pt(111) give conflicting information on preferred paths and final states. Here we report large p(4 × 4) unit cell minimum energy pathway evaluations and compare O(2) adsorption and dissociated states on Pt(111). Calculations reveal how the pathways for O(2) dissociation starting from top-fcc-bridge, top-hcp-bridge, and top-bridge-top sites are interconnected. They also provide a direct reaction pathway for the dissociation of an O(2) molecule from a top-fcc-bridge into an hcp and an fcc site, which is consistent with low temperature scanning tunneling microscope experiments. Such a pathway is shown to be considerably perturbed by the presence of co-adsorbed oxygen atoms. We quantify the coverage dependence through the construction of a Brønsted-Evans-Polanyi relationship relating the O(2) dissociation activation energies to the binding energies of the dissociated O atoms. We also show that all pathways starting from a top-fcc-bridge site give the smallest barriers for O(2) dissociation.

Implications of coverage-dependent O adsorption for catalytic NO oxidation on the late transition metals

“…We have found that O 2 dissociation activation energies, E a,i , for these dissociation events on Pt(111) can be correlated to the overall reaction energy ΔE i using a BEP relationship. 5,6,13…”

CO Oxidation over Strained Pt(100) Surface: A DFT Study

“…At least at low O coverage, O 2 automatically dissociates on low-index Pt surfaces such as (111), (100), (321) [48][49][50]. Although O adsorption is much stronger than CO adsorption, their coadsorption has exemplified the change of favorable binding site of O.…”

Theoretical investigation of the effect of OH− ions on O2 adsorption on low-index Pt surfaces in alkaline solution

“…Computer simulation provides an alternative method to explore the ORR mechanism and a theoretical supplement for state-of-art experimental techniques. Extensive theoretical studies on the O 2 adsorption and ORR mechanism have been reported [16][17][18][19][20][21][22][23]. However, most of them employed the DFT method, which cannot explicitly consider the effect of bulk solvent and obtain the dynamic information of adsorption interface.…”