Efficient Conversion and Storage of Marine Renewable Energy - Hydrogen Production by Electrolysis of Seawater

Abstract To address the energy crisis caused by over-reliance on fossil energy, the development of marine renewable energy needs to solve the problems of high transmission costs and unstable output, and seawater electrolysis for hydrogen production emerges as a key solution. Traditional hydrogen production via water electrolysis relies on scarce freshwater, while seawater is an abundant resource and direct seawater electrolysis is more efficient. This article outlines the technical routes of indirect and direct electrolysis of seawater, as well as the characteristics of the three electrolysis technologies (AWE, PEMWE, and AEMWE). It analyzes the challenges of direct seawater electrolysis, including anodic competitive reactions, chloride ion corrosion, and cathodic cation precipitation. It elaborates on technological breakthroughs such as innovations in electrode materials and optimization of electrolysis systems, and introduces demonstration projects of coupled hydrogen production with marine new energy in Europe and China. In the future, interdisciplinary integration will help this technology break through industrialization bottlenecks, release the potential of Marine economy, and promote the global energy transition.