3D-ordered catalytic nanoarrays interlocked on anion exchange membranes for water electrolysis

Abstract

High-performance membrane electrode assemblies (MEAs) have significant importance for developing anion exchange membrane (AEM) water electrolysis, however, the fabrication of nanostructured MEAs to increase catalyst utilization, maximize three-phase boundaries, enhance mass transport and improve electrolysis stability remains a fundamental challenge. Here, we propose a swelling-assisted transfer strategy to construct ordered anodic catalyst layers (ACLs) on an AEM. Concretely, utilizing a three-dimensionally interlocked ACL/AEM interface formed using a direct membrane deposition method, the ordered ACLs can be perfectly transferred to AEMs at atmospheric pressure and low temperature, thus enabling MEAs with vertically oriented through-hole ACL structures and an aligned ionomer layer for OH⁻ transfer. Using the prepared MEA in AEM water electrolyzers, we obtain a current density of 3.61 A cm⁻² at 2.0 V under pure-water-fed conditions, and stable operation for 700 h at a current density of 1.0 A cm⁻² at ∼1.7 V. This work provides a universal approach to construct next-generation MEAs for membrane-based electrochemical devices.