Abstract Breaking the activity‐stability trade‐off in acidic oxygen evolution reaction (OER) is pivotal for realizing industrial‐grade proton exchange membrane water electrolyzers (PEMWEs). Herein, we report amorphous/crystalline Ru 0.3 Ir 0.7 O x nanorods (a/c‐Ru 0.3 Ir 0.7 O x NRs) synthesized via ion exchange and thermal annealing. The a/c‐Ru 0.3 Ir 0.7 O x NRs showed a 229 mV overpotential at 10 mA/cm 2 . In PEMWEs, the catalyst achieved cell voltages of 1.56 and 1.77 V at 1.0 and 3.0 A/cm 2 , respectively, and demonstrated stable operation for 350 h at 1.0 A/cm 2 , outperforming most previous reports. Characterization reveals RuO 2 in crystalline microdomains and IrO ₓ in amorphous regions. In situ studies clearly showed that the OER on a/c‐Ru 0.3 Ir 0.7 O x NRs proceeds via a hybrid mechanism combining lattice oxygen oxidation (LOM) and adsorbate evolution mechanism (AEM), avoiding the disadvantages of the exclusive LOM and AEM pathways in amorphous (a‐Ru 0.3 Ir 0.7 O x NRs) and crystalline (c‐Ru 0.3 Ir 0.7 O x NRs) counterparts and facilitating practical PEMWE application.
Liu et al. (Mon,) studied this question.