Abstract
The ridge at the intersection of two adjacent non-equivalent facets of single crystalline particles holds great potential to harmonize catalytic activity and durability. However, conventional facet engineering usually yields crystals with sparse ridges, impeding ridge catalysis. Here, we implement a programmed growth strategy via a decomposable evaporative eutectic system, enabling alternating BFDH-driven -preferential growth and Wulff-guided -preferential growth in pentlandite to produce dense ridges between {111} and {200} facets. The facet-dependent surface reconstruction induces the selective formation of NiOOH and (Fe,Ni)OOH on the {111} and {200} facets, respectively, to create highly active NiOOH/(Fe,Ni)OOH interfacial sites precisely at their ridges, which overcomes the Fe/Ni-equivalent homogeneity constraints of pentlandite to unlock its activities in oxygen evolution reaction (186 mV at 10 mA cm-2 and >1000 h stability at 100 mA cm-2). In an anion-exchange membrane water electrolyzer, such pentlandite microcrystals deliver the current density of 1.0 A cm-2 at 1.95 V with 160 h stability at 500 mA cm-2. This work establishes ridge engineering as a paradigm for stable, high-activity catalysts.