Recent advances of ruthenium-based materials for acidic oxygen evolution reaction: from catalyst design to proton exchange membrane water electrolyser

Abstract

Harvesting the renewable energy to split water offers an ideal approach to the production of clean hydrogen energy. Among various water electrolysis devices, proton exchange membrane water electrolyser (PEMWE) with a high current density, quick response operation, and compact design has attracted much attention. The anodic oxygen evolution reaction (OER) in acidic electrolyte seriously relies on the iridium-based catalyst, but is limited to its scarcity and high cost. Ruthenium (Ru)-based catalyst has been considered as the most promising candidate to replace Ir in acidic OER, due to its low cost and high activity. Nevertheless, there is still much room to enhance the OER activity and durability of Ru-based catalysts for the practical application in PEMWE. Herein, we first give a brief introduction of main configuration and operating factors of PEMWE. Then we discuss three OER mechanisms and degradation reason of Ru-based catalyst in acid. Aftereards, the performance improvement strategies of Ru-based acidic OER catalysts are emphatically summarized. We further spotlight some typical examples of PEMWEs using Ru-based OER catalysts as anode. Finally, the further challenges and directions for the development of high-performance Ru-based OER catalysts in PEMWE are offered and speculated.