Modulating fcc and hcp Ruthenium on the Surface of Palladium–Copper Alloy through Tunable Lattice Mismatch

Abstract

Herein, we report an epitaxial-growth-mediated method to grow face-centered cubic (fcc) Ru, which is thermodynamically unfavorable in the bulk form, on the surface of Pd-Cu alloy. Induced by the galvanic replacement between Ru and Pd-Cu alloy, a shape transformation from a Pd-Cu@Ru core-shell to a yolk-shell structure was observed during the epitaxial growth. The successful coating of the unconventional crystallographic structure is critically dependent on the moderate lattice mismatch between the fcc Ru overlayer and PdCu3 alloy substrate. Further, both fcc and hexagonal close packed (hcp) Ru can be selectively grown through varying the lattice spacing of the Pd-Cu substrate. The presented findings provide a new synthetic pathway to control the crystallographic structure of metal nanomaterials.

Gold‐Doping of Double‐Crown Pd Nanoclusters

“…Heteroatoms doping has been demonstrated as an effective strategyt oe nhancea nd enrich the properties of metal nanoparticles. [1][2][3][4][5][6][7][8] Recently,a tomically precise doping of ultra small metal nanoparticles (so-called nanoclusters)h as received extensivei nterest, owing to the subtle tuning of their compositions, structures, and properties, the in-depthu nderstandingo f the doping effect, and significant efforts have been devotedt o the doping of group 11 metal nanoclusters such as Au 25 (SR) 18 , Au 38 (SR) 24 ,A g 44 (SR) 30 and Ag 25 (SR) 18 (SR:t hiolate), among which heteroatoms alwaysr eplace the substrate atoms in ao ne to one fashion. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Although thiolated group 10 transition metal (Ni, Pd,a nd Pt) nanoclustersh ave been known for over half a century, [25][26][27][28][29] the doped double-crown structure remainsu nraveled by single crystal X-ray crystallography (SCXC) and the doping influence on the compositions, structures, and properties of Ni, Pd, or Ptnanoclustersi sy et to be known.…”

Three‐Dimensional Branched and Faceted Gold–Ruthenium Nanoparticles: Using Nanostructure to Improve Stability in Oxygen Evolution Electrocatalysis

“…[13] TheTEM image of the core-branch interface (Supporting Information, Figure S3) shows that hcp branches grow along the c-axis from the fcc core.Notably,close-packed hcp planes on the Ru branches do not align with close-packed fcc planes of the core.I nstead, branches connect to the core through a1nm shell and have arandom arrangement independent of the crystal facets on the Au core surface.This is in contrast to CdS,C dSe,a nd Ni NPs where hcp {0001} planes of the branches grow off the {111} faces of fcc cores. [17] The1nm Ru shell has stacking faults that offset the strain between these mismatched planes,e nabling branching via adifference in crystal structure. [17] The1nm Ru shell has stacking faults that offset the strain between these mismatched planes,e nabling branching via adifference in crystal structure.…”

Surface Atomic Regulation of Core–Shell Noble Metal Catalysts

“…As shown in Figure a, an epitaxial‐growth‐mediated approach was developed by Yao et al. to modulate the face‐centered cubic (fcc) and hexagonal close packed (hcp) Ru on the surface of Pd–Cu nanoparticles (Pd–Cu@Ru core–shell NPs) . Interestingly, Pd–Cu@Ru yolk–shell structures were prepared by galvanic replacement reaction, and maintained the Ru shell with the fcc structure.…”

“… a) Schematic illustration of the structure evolution of Pd–Cu@Ru yolk–shell NPs and the corresponding TEM images of the samples observed at three representative stages: PdCu 3 seed (left), Pd–Cu@Ru core–shell NPs (middle), and Pd–Cu@Ru yolk–shell NPs (right). Reproduced with permission . Copyright 2016, Wiley‐VCH.…”