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Materials Data on IrRu by Materials Project

RuIr is Magnesium-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Ru is bonded to six equivalent Ru and six equivalent Ir atoms to form RuIr6Ru6 cuboctahedra that share corners with eighteen equivalent RuIr6Ru6 cuboctahedra, edges with six equivalent RuIr6Ru6 cuboctahedra, edges with twelve equivalent IrIr6Ru6 cuboctahedra, faces with eight equivalent RuIr6Ru6 cuboctahedra, and faces with twelve equivalent IrIr6Ru6 cuboctahedra. All Ru–Ru bond lengths are 2.75 Å. All Ru–Ir bond lengths are 2.70 Å. Ir is bonded to six equivalent Ru and six equivalent Ir atoms to form IrIr6Ru6 cuboctahedra that share corners with eighteen equivalent IrIr6Ru6 cuboctahedra, edges with six equivalent IrIr6Ru6 cuboctahedra, edges with twelve equivalent RuIr6Ru6 cuboctahedra, faces with eight equivalent IrIr6Ru6 cuboctahedra, and faces with twelve equivalent RuIr6Ru6 cuboctahedra. All Ir–Ir bond lengths are 2.75 Å.

36 MATERIALS SCIENCE↗

Materials Data on IrRu by Materials Project

RuIr is Copper-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Ru sites. In the first Ru site, Ru is bonded to six equivalent Ru and six Ir atoms to form RuIr6Ru6 cuboctahedra that share corners with twelve RuIr6Ru6 cuboctahedra, edges with twelve RuIr6Ru6 cuboctahedra, edges with twelve IrIr6Ru6 cuboctahedra, faces with six equivalent RuIr6Ru6 cuboctahedra, and faces with twelve IrIr6Ru6 cuboctahedra. All Ru–Ru bond lengths are 2.72 Å. All Ru–Ir bond lengths are 2.72 Å. In the second Ru site, Ru is bonded to ten equivalent Ru and six Ir atoms to form RuIr6Ru10 cuboctahedra that share corners with ten IrIr6Ru6 cuboctahedra, corners with twelve RuIr6Ru6 cuboctahedra, edges with eight IrIr6Ru6 cuboctahedra, edges with sixteen RuIr6Ru6 cuboctahedra, faces with sixteen equivalent RuIr6Ru10 cuboctahedra, and faces with eighteen IrIr6Ru6 cuboctahedra. There are a spread of Ru–Ru bond distances ranging from 2.72–5.43 Å. All Ru–Ir bond lengths are 2.72 Å. There are three inequivalent Ir sites. In the first Ir site, Ir is bonded to six equivalent Ru and six equivalent Ir atoms to form IrIr6Ru6 cuboctahedra that share corners with twelve IrIr6Ru6 cuboctahedra, edges with twelve equivalent RuIr6Ru6 cuboctahedra, edges with twelve IrIr6Ru6 cuboctahedra, faces with six equivalent IrIr6Ru6 cuboctahedra, and faces with twelve equivalent RuIr6Ru6 cuboctahedra. All Ir–Ir bond lengths are 2.72 Å. In the second Ir site, Ir is bonded to six Ru and six equivalent Ir atoms to form IrIr6Ru6 cuboctahedra that share corners with five equivalent RuIr6Ru10 cuboctahedra, corners with twelve IrIr6Ru6 cuboctahedra, edges with ten RuIr6Ru6 cuboctahedra, edges with twelve IrIr6Ru6 cuboctahedra, faces with six equivalent IrIr6Ru6 cuboctahedra, and faces with fifteen RuIr6Ru6 cuboctahedra. All Ir–Ru bond lengths are 2.72 Å. All Ir–Ir bond lengths are 2.72 Å. In the third Ir site, Ir is bonded to six Ru and six equivalent Ir atoms to form IrIr6Ru6 cuboctahedra that share corners with five equivalent RuIr6Ru10 cuboctahedra, corners with twelve IrIr6Ru6 cuboctahedra, edges with ten RuIr6Ru6 cuboctahedra, edges with twelve IrIr6Ru6 cuboctahedra, faces with six equivalent IrIr6Ru6 cuboctahedra, and faces with fifteen RuIr6Ru6 cuboctahedra. All Ir–Ir bond lengths are 2.72 Å.

36 MATERIALS SCIENCE↗

Atomically Local Electric Field Induced Interface Water Reorientation for Alkaline Hydrogen Evolution Reaction

The slow water dissociation process in alkaline electrolyte severely limits the kinetics of HER. The orientation of H 2 O is well known to affect the dissociation process, but H 2 O orientation is hard to control because of its random distribution. Herein, an atomically asymmetric local electric field was designed by IrRu dizygotic single-atom sites (IrRu DSACs) to tune the H 2 O adsorption configuration and orientation, thus optimizing its dissociation process. The electric field intensity of IrRu DSACs is over 4.00×10 10 N/C. The ab initio molecular dynamics simulations combined with in situ Raman spectroscopy analysis on the adsorption behavior of H 2 O show that the M–H bond length (M=active site) is shortened at the interface due to the strong local electric field gradient and the optimized water orientation promotes the dissociation process of interfacial water. This work provides a new way to explore the role of single atomic sites in alkaline hydrogen evolution reaction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

A versatile and practical synthesis of oxygen evolution catalysts

State-of-the-art OER (oxygen evolution reaction) catalyst syntheses require the use of expensive metals (i.e. Ir) with complex and time-consuming synthetic routes, difficulty in control, and impractical yields. Although some reported catalysts show improved performance (i.e. activity, stability, lowering Ir content with Ru), their synthesis is costly and not viable for scale-up. Here we demonstrate a practical, reliable, and scalable one-pot synthesis method for OER catalysts based on borohydride reduction to quickly yield >100 mg of Ir, Ru, and IrRu nanoparticles (1.6 ± 0.2 nm) with outstanding batch-to-batch consistency. Both mono- and bi-metallic compositions exhibit a metal-core/metal-oxide-shell nanoparticle structure. We further demonstrate the versatility of this method by incorporating earth-abundant yttrium, resulting in a catalyst with improved precious metal utilization for OER. This method serves as a robust platform for generating ultrasmall (<2 nm) multi-metal particles useful for electrocatalysis research.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗