High Selectivity Electrocatalysts for Oxygen Evolution Reaction and Anti-Chlorine Corrosion Strategies in Seawater Splitting

Yang Liu,Shanshan Jiang,Chao Su,Zongping Shao,Hao Qiu

doi:10.3390/catal12030261

Abstract

Seawater is one of the most abundant and clean hydrogen atom resources on our planet, so hydrogen production from seawater splitting has notable advantages. Direct electrolysis of seawater would not be in competition with growing demands for pure water. Using green electricity generated from renewable sources (e.g., solar, tidal, and wind energies), the direct electrolytic splitting of seawater into hydrogen and oxygen is a potentially attractive technology under the framework of carbon-neutral energy production. High selectivity and efficiency, as well as stable electrocatalysts, are prerequisites to facilitate the practical applications of seawater splitting. Even though the oxygen evolution reaction (OER) is thermodynamically favorable, the most desirable reaction process, the four-electron reaction, exhibits a high energy barrier. Furthermore, due to the presence of a high concentration of chloride ions (Cl−) in seawater, chlorine evolution reactions involving two electrons are more competitive. Therefore, intensive research efforts have been devoted to optimizing the design and construction of highly efficient and anticorrosive OER electrocatalysts. Based on this, in this review, we summarize the progress of recent research in advanced electrocatalysts for seawater splitting, with an emphasis on their remarkable OER selectivity and distinguished anti-chlorine corrosion performance, including the recent progress in seawater OER electrocatalysts with their corresponding optimized strategies. The future perspectives for the development of seawater-splitting electrocatalysts are also demonstrated.

Highlights

Current global energy supplies are mainly obtained from traditional fossil fuels such as coal, crude oil, and natural gas
For the oxygen evolution reaction (OER), it involves a four-electron transfer process that inevitably leads to a high energy barrier and exhibits sluggish kinetics for seawater electrolysis
The oxygen yield during OERs using a CoMn layered double hydroxide (LDH) catalyst was quantified in a 5-h electrolysis experiment, measured with a fluorescence O2 detector (Figure 3e)

Summary

Introduction

Current global energy supplies are mainly obtained from traditional fossil fuels such as coal, crude oil, and natural gas. The electrolysis of water produces hydrogen at the cathode, it is strongly dependent on the efficiency and stability of the OER at the anode. For the OER, it involves a four-electron transfer process that inevitably leads to a high energy barrier and exhibits sluggish kinetics for seawater electrolysis.

Results

Conclusion