Unique catalytic decomposition and reduction of hydrogen peroxide and organic peroxides on magnesia (001) promoted by oxide-metal hybrid nanostructure

TL;DR

This study uses density-functional theory to explore how ultrathin magnesia films on transition metals catalyze the dissociation and reduction of hydrogen peroxide and organic peroxides, revealing factors influencing reactivity and potential applications.

Contribution

First detailed computational analysis of hydrogen peroxide dissociation on magnesia/metal hybrid nanostructures, highlighting the effects of film thickness and metal substrate on catalytic activity.

Findings

Dissociative adsorption of hydrogen peroxide is thermodynamically favorable on MgO(001)/TM.

Thinner oxide films exhibit higher reactivity for peroxide dissociation.

Metal substrate choice influences the strength of peroxide chemisorption.

Abstract

The detection, removal and reduction of hydrogen peroxide is of significant importance for its increasing application in the areas of environment, food, electrochemistry and clinical laboratory. Herein the dissociative adsorption behavior of hydrogen peroxide on ultrathin magnesia (001) films deposited on transition metal is uncovered for the first time by employing periodic density-functional theory calculations with van der Waals corrections. The hydrogen peroxide is dissociated smoothly and reduced to surface hydroxyls on MgO(001)/TM, and the dissociative adsorption energies of all the considered fragmentation configurations are substantially negative, demonstrating dissociation and reduction of hydrogen peroxide on MgO(001)/TM is thermodynamically favorable. The dissociative adsorption energy decreases monotonously with increasing film thickness, demonstrating the lower reactivity of thick oxide films. Moreover, we examined the suitability of several transition metal slabs (molybdenum, silver, vanadium, tungsten and gold) combined with magnesia for splitting hydrogen peroxide. The dissociative adsorption energies enhance when the lattice constants of substrate slabs increase, indicating the chemisorption strength can be tuned by category of metal slabs as well as thickness of oxide film. The mechanism of reactivity enhancement for energetically and dynamically favorable decomposition of hydrogen peroxide on supported magnesia is elucidated by characterizing the geometric structures and electronic properties. The fragmentation and reduction of diethyl peroxide and peroxyacetone are also studied to reveal the catalytic activity of ultrathin magnesia toward splitting organic peroxides. The results are wished to provide useful clue for detecting and reducing hydrogen peroxide and organic peroxides by employing oxide-metal hybrid nanostructure.