Rational design of oxygen evolution reaction catalysts for seawater electrolysis

Compared with the splitting of freshwater, seawater electrolysis is more significant because it is a ‘two birds with one stone’ technology for both hydrogen generation and seawater desalination. The challenges of seawater electrolysis include degraded activity, low selectivity, and poor catalytic durability. Three effective strategies, including designing 3D hierarchical porous structures, employing protective layers, and engineering surface wettability, are discussed to synthesize efficient and stable OER catalysts for seawater electrolysis. Rationally designed OER catalysts with sufficient active sites, efficient electron and mass transport, and a protective layer against chloride ions are good candidates for seawater electrolysis. Water electrolysis provides a promising route to produce high energy density hydrogen. Compared with the limited amount of fresh water, seawater is an abundant resource that has attracted increasing attention for electrolysis. However, seawater electrolysis has thus far suffered from degraded activity and stability, and from low oxygen evolution reaction (OER) selectivity, due to the existence of chloride ions and insoluble solids in seawater. This short review summarizes trends in the rational design of OER catalysts, providing some effective strategies, including constructing 3D hierarchical porous structures, employing protective layers, and engineering surface wettability, to synthesize efficient and stable OER catalysts for seawater electrolysis. Finally, a perspective regarding designing high-performance catalysts for seawater electrolysis is also provided. Water electrolysis provides a promising route to produce high energy density hydrogen. Compared with the limited amount of fresh water, seawater is an abundant resource that has attracted increasing attention for electrolysis. However, seawater electrolysis has thus far suffered from degraded activity and stability, and from low oxygen evolution reaction (OER) selectivity, due to the existence of chloride ions and insoluble solids in seawater. This short review summarizes trends in the rational design of OER catalysts, providing some effective strategies, including constructing 3D hierarchical porous structures, employing protective layers, and engineering surface wettability, to synthesize efficient and stable OER catalysts for seawater electrolysis. Finally, a perspective regarding designing high-performance catalysts for seawater electrolysis is also provided. the reaction that generates molecular chlorine on the anode. the reaction that generates molecular hydrogen on the cathode. the reaction that generates molecular oxygen on the anode. the preferential permeation of certain ionic species through ion-exchange membranes. the preferential outcome of a chemical reaction over a set of possible alternative reactions. High selectivity suggests low occurrence of side reactions.