Seawater Electrolysis

Abstract

The rising demand for renewable hydrogen is driving up water requirements globally so seawater is considered as a potential water source for electrolysis. There are two main approaches to seawater electrolysis: (1) direct seawater electrolysis, where seawater is fed directly into the stack, and (2) indirect seawater electrolysis, where desalinated seawater is used. For direct seawater electrolysis, it is essential to develop advanced anode catalysts that favor the oxygen evolution reaction (OER) over the chlorine oxidation reaction (COR). The current density and system costs are also key considerations. The indirect seawater electrolysis resembles the conventional electrolysis but includes a seawater desalination step. The combination of offshore wind and PEM electrolysis is gaining interest as a preferred method for renewable hydrogen production especially in Europe.