Results for “IrPt” | Engineering Papers

DOE OSTI2020

Materials Data on IrPt by Materials Project

PtIr crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Ir sites. In the first Ir site, Ir is bonded to six equivalent Ir and six equivalent Pt atoms to form IrIr6Pt6 cuboctahedra that share corners with twelve IrIr6Pt6 cuboctahedra, edges with twelve IrIr6Pt6 cuboctahedra, edges with twelve equivalent PtIr6Pt6 cuboctahedra, faces with six equivalent IrIr6Pt6 cuboctahedra, and faces with twelve equivalent PtIr6Pt6 cuboctahedra. All Ir–Ir bond lengths are 2.78 Å. All Ir–Pt bond lengths are 2.77 Å. In the second Ir site, Ir is bonded to six equivalent Ir and six Pt atoms to form IrIr6Pt6 cuboctahedra that share corners with five equivalent PtIr6Pt10 cuboctahedra, corners with twelve IrIr6Pt6 cuboctahedra, edges with ten PtIr6Pt6 cuboctahedra, edges with twelve IrIr6Pt6 cuboctahedra, faces with six equivalent IrIr6Pt6 cuboctahedra, and faces with fifteen PtIr6Pt6 cuboctahedra. All Ir–Ir bond lengths are 2.78 Å. All Ir–Pt bond lengths are 2.77 Å. In the third Ir site, Ir is bonded to six equivalent Ir and six Pt atoms to form IrIr6Pt6 cuboctahedra that share corners with five equivalent PtIr6Pt10 cuboctahedra, corners with twelve IrIr6Pt6 cuboctahedra, edges with ten PtIr6Pt6 cuboctahedra, edges with twelve IrIr6Pt6 cuboctahedra, faces with six equivalent IrIr6Pt6 cuboctahedra, and faces with fifteen PtIr6Pt6 cuboctahedra. All Ir–Ir bond lengths are 2.78 Å. All Ir–Pt bond lengths are 2.77 Å. There are two inequivalent Pt sites. In the first Pt site, Pt is bonded to six Ir and six equivalent Pt atoms to form PtIr6Pt6 cuboctahedra that share corners with twelve PtIr6Pt6 cuboctahedra, edges with twelve IrIr6Pt6 cuboctahedra, edges with twelve PtIr6Pt6 cuboctahedra, faces with six equivalent PtIr6Pt6 cuboctahedra, and faces with twelve IrIr6Pt6 cuboctahedra. All Pt–Pt bond lengths are 2.78 Å. In the second Pt site, Pt is bonded to six Ir and ten equivalent Pt atoms to form PtIr6Pt10 cuboctahedra that share corners with ten IrIr6Pt6 cuboctahedra, corners with twelve PtIr6Pt6 cuboctahedra, edges with eight IrIr6Pt6 cuboctahedra, edges with sixteen PtIr6Pt6 cuboctahedra, faces with sixteen equivalent PtIr6Pt10 cuboctahedra, and faces with eighteen IrIr6Pt6 cuboctahedra. There are a spread of Pt–Pt bond distances ranging from 2.78–5.57 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Hierarchical Polyelemental Nanoparticles as Bifunctional Catalysts for Oxygen Evolution and Reduction Reactions

Efficient electrocatalysts are critical in various clean energy conversion and storage systems. Polyelemental nanomaterials are attractive as multi-functional catalysts due to their wide compositions and synergistic properties. However, controlled synthesis of polyelemental nanomaterials is difficult due to their complex composition. Herein, we present a one-step synthetic strategy to fabricate a hierarchical polyelemental nanomaterial, which contains ultrasmall precious metal nanoparticles (IrPt, ~5 nm) anchored on spinel-structure transition metal oxide nanoparticles. The polyelemental nanoparticles serve as excellent bifunctional catalysts for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). The mass catalytic activity of the polyelemental nanoparticles is 7-times higher than that of Pt in ORR and 28-times that of Ir in OER at the same overpotentials, demonstrating the high activity of the bifunctional electrocatalyst. We attribute this outstanding performance to the controlled multiple elemental composition, mixed chemical states, and large electroactive surface area. The hierarchical nanostructure and polyelemental design of these nanoparticles offers a general and powerful alternative material for catalysis, solar cells, and more.

25 ENERGY STORAGE↗