Selective electrochemical production of hydrogen peroxide at zigzag edges of exfoliated molybdenum telluride nanoflakes.

Xuan Zhao,Tingting Wang,Yanguang Li,Yunli Da,Wu Zhou,Xiaoyun He,Yu Wang,Xinxia Wang,Mingquan Xu,Jonathan N Coleman,Yafei Li

doi:10.1093/nsr/nwaa084

Abstract

The two-electron reduction of molecular oxygen represents an effective strategy to enable the green, mild and on-demand synthesis of hydrogen peroxide. Its practical viability, however, hinges on the development of advanced electrocatalysts, preferably composed of non-precious elements, to selectively expedite this reaction, particularly in acidic medium. Our study here introduces 2H-MoTe2 for the first time as the efficient non-precious-metal-based electrocatalyst for the electrochemical production of hydrogen peroxide in acids. We show that exfoliated 2H-MoTe2 nanoflakes have high activity (onset overpotential ∼140 mV and large mass activity of 27 A g−1 at 0.4 V versus reversible hydrogen electrode), great selectivity (H2O2 percentage up to 93%) and decent stability in 0.5 M H2SO4. Theoretical simulations evidence that the high activity and selectivity of 2H-MoTe2 arise from the proper binding energies of HOO* and O* at its zigzag edges that jointly favor the two-electron reduction instead of the four-electron reduction of molecular oxygen.

Highlights

Hydrogen peroxide (H2O2) is a potential energy carrier and an important commodity chemical with high industrial value [1,2]
We demonstrate that 2H-phase molybdenum telluride (MoTe2) nanoflakes, synthesized from bulk powder via ultrasonication-assisted liquid phase exfoliation, acts as an efficient 2e-oxygen reduction reaction (ORR) electrocatalyst in acids
Even though synthesis of high-quality MoTe2 nanosheets or nanoflakes by chemical vapor deposition (CVD) has been reported in literature [30,31], such a high-temperature bottom-up approach is seriously limited by its complexity and low production yield

Summary

Introduction

Hydrogen peroxide (H2O2) is a potential energy carrier and an important commodity chemical with high industrial value [1,2]. We show that exfoliated 2H-MoTe2 nanoflakes have high activity (onset overpotential ∼140 mV and large mass activity of 27 A g−1 at 0.4 V versus reversible hydrogen electrode), great selectivity (H2O2 percentage up to 93%) and decent stability in 0.5 M H2SO4.

Results

Conclusion