Micellar Brush-Directed Oxophilic Zr-Doped RuO Nanoarrays for Durable Acidic Oxygen Evolution Reaction.

Although being considered as a promising alternative to iridium-based catalysts in proton exchange membrane water electrolysis (PEM-WE), cost-effective ruthenium (Ru)-based anodic catalysts generally lack sufficient stability for harsh operating conditions. Here, we developed a facile method to fabricate erect nanoarrays of interweaved nanorods of zirconium-doped ruthenium oxide (ZrRuO) for long-term industrial-level oxygen evolution reaction (OER). This is accomplished by the spontaneous and abundant accumulation of Ru nanoparticles and Zr ions in pyridine-rich micellar brushes through coordination interactions, followed by direct calcination in air. The uniform dispersion of Ru and Zr precursors promotes the homogeneous doping of Zr in the resulting RuO nanoarray and the formation of Zr-O-Ru bridging oxygen structures. The oxophilic Zr strengthens the stability of the lattice oxygen and prevents its participation in OER. Meanwhile, it also leads to electron deficiency of the bridging Ru sites and facilitates the adsorption of HO molecules and the subsequent dissociation into *OH, thus enhancing the OER stability and activity. Notably, the nanoarray architecture synergistically restricts the voltage loss caused by electron and mass transport. Consequently, the ZrRuO-nanoarrays enabled a remarkably low PEM-WE potential of 1.64 V at 1.2 A cm with a negligible degradation rate (26 µV h, over 1000 h).