State-of-the-art iridium-based catalysts for acidic water electrolysis: a minireview of wet-chemistry synthesis methods

With the increasing demand for clean hydrogen production, both as a fuel and an indispensable reagent for chemical industries, acidic water electrolysis has attracted considerable attention in academic and industrial research. Iridium is a well-accepted active and corrosion-resistant component of catalysts for oxygen evolution reaction (OER). However, its scarcity demands breakthroughs in catalyst preparation technologies to ensure its most efficient utilization. This minireview focusses on the wet-chemistry synthetic methods of the most active and (potentially) durable Ir catalysts for acidic OER, selected from the recent publications in the open literature. The catalysts are classified by their synthesis methods, with authors' opinion on their practicality. The review may also guide the selection of the state-of-the-art Ir catalysts for benchmarking purposes.