1T′-MoTe2 monolayer: A promising two-dimensional catalyst for the electrochemical production of hydrogen peroxide

Abstract

The direct synthesis of hydrogen peroxide (H2O2) via a two-electron oxygen reduction reaction (2e-ORR) in acidic media has emerged as a green process for the production of this valuable chemical. However, such an approach employs expensive noble-metal-based electrocatalysts, which severely undermines its feasibility when implemented on an industrial scale. Herein, based on density functional theory computations and microkinetic modeling, we demonstrate that a novel two-dimensional (2D) material, namely a 1T′-MoTe2 monolayer, can serve as an efficient non-precious electrocatalyst to facilitate the 2e-ORR. The 1T′-MoTe2 monolayer is a stable 2D crystal that can be easily produced through exfoliation techniques. The surface-exposed Te sites of the 1T′-MoTe2 monolayer exhibit a favorable OOH* binding energy of 4.24 eV, resulting in a rather high basal plane activity toward the 2e-ORR. Importantly, kinetic computations indicate that the 1T'-MoTe2 monolayer preferentially promotes the formation of H2O2 over the competing four-electron ORR step. These desirable characteristics render 1T′-MoTe2 a promising candidate for catalyzing the electrochemical reduction of O2 to H2O2.