Abstract
Proton exchange membrane water electrolysis is a promising technology to produce green hydrogen from renewables, as it can efficiently achieve high current densities. Lowering iridium amount in oxygen evolution reaction electrocatalysts is critical for achieving cost-effective production of green hydrogen. In this work, we develop catalysts from Ir double perovskites. Sr
2
CaIrO
6
achieves 10 mA cm
−2
at only 1.48 V. The surface of the perovskite reconstructs when immersed in an acidic electrolyte and during the first catalytic cycles, resulting in a stable surface conformed by short-range order edge-sharing IrO
6
octahedra arranged in an open structure responsible for the high performance. A proton exchange membrane water electrolysis cell is developed with Sr
2
CaIrO
6
as anode and low Ir loading (0.4 mg
Ir
cm
−2
). The cell achieves 2.40 V at 6 A cm
−2
(overload) and no loss in performance at a constant 2 A cm
−2
(nominal load). Thus, reducing Ir use without compromising efficiency and lifetime.
While water splitting offers a renewable means to produce H
2
fuel, most electrolyzers rely on scarce elements to function. Here, authors study low-content Iridium catalysts derived from mixed oxides for proton exchange membrane water electrolysis anodes without compromising activity and durability.