Surface Reactivity Enhancement by O2 Dissociation on a Single-layer MgO Film Deposited on Metal Substrate

TL;DR

This study demonstrates that a single-layer MgO film on a metal substrate significantly enhances surface reactivity by enabling complete O2 dissociation, which can trigger subsequent catalytic reactions.

Contribution

First-principles calculations reveal that O2 dissociates on single-layer MgO, unlike thicker films, providing new insights into surface catalysis on insulating materials.

Findings

O2 fully dissociates on single-layer MgO

Dissociated O2 penetrates interfacial region

Water reacts with interfacial oxygen forming hydroxyl radicals

Abstract

Improving reactivity on an insulating surface is crucial due to their important applications in surface catalytic reactions. In this work, we carried out first-principles calculations to investigate the adsorption of O2 on a single-layer MgO(100) film deposited on metal substrate. The adsorption configurations, reaction pathways, molecular dynamics simulations, and electronic properties are reported. We reveal that O2 can completely dissociate on the surface, which is in sharp contrast to that on MgO(100) films thicker than one monolayer. The dissociated O2 tends to penetrate into the interfacial region, behaving like a switch to trigger subsequent chemical reactions. As an example, the interplay between water and the interfacial oxygen results in the formation of hydroxyl radicals. This study paves an avenue to accomplish the desired surface catalytic reactions, especially those involving oxygen.