Oxygen evolution reaction electrocatalysts for seawater splitting: A review

Abstract

The hydrogen economy as a sustainable energy future has been developed for decades. Driven by renewable energy sources such as solar energy and wind energy, hydrogen generation from water electrolysis is expected to truly achieve the goal of carbon neutrality, among which direct splitting of seawater is of increasing significance since the naturally abundant feedstock. With a typical overall salinity reaching ∼3.5 wt% and a pH around 8, the challenges of seawater electrolysis lie not only in the kinetically sluggish oxygen evolution reaction (OER), but also in the competition of chloride-ions oxidation reaction (CER). In this review, an overview of the latest developments in seawater splitting was outlined. Firstly, the challenges inhabiting the progress in seawater electrolysis such as detrimental chlorine evolution reaction and unfavorable insoluble precipitates formation were pictured, followed by a brief introduction to the state-of-the-art advances in water electrolysis. Next, a framework that was expected to realize the large-scale industrialization of seawater electrolysis was described based on several effective strategies for seawater decomposition. Benefiting from the efficiently tunable structure–activity relationship, OER electrocatalysts in the seawater-splitting scenario will bring widespread prosperity to the hydrogen economy.