Anode Reinforcement by Polydopamine Glue in Anion Exchange Membrane Water Electrolysis

Abstract

Durable catalyst layers (CLs) are essential for the commercialization of anion exchange membrane water electrolyzers (AEMWEs). However, the insufficient binding strengths of typical anion exchange ionomers often lead to CL disintegration and detachment from porous transport layers, resulting in rapid performance deterioration during the early stage of operation. Herein, coating the anode CL with polydopamine (PDA) is proposed as a solution to this problem; the coating enhances the mechanical integrity of the anode CL and its interfacial adhesion to the porous transport layer through electronic interactions. Furthermore, the aerophobic property of PDA helps remove O-2 bubbles from the catalyst surface to improve the AEMWE performance. An AEMWE with the PDA coating exhibits stable operation for 300 h without any sign of initial degradation while maintaining high energy efficiency (>91.6%, higher heating value), underscoring the importance of the mechanical robustness and interfacial adhesion of the anode CL for achieving high-durability AEMWEs.