LAUSR

Abstract The current study extends the insight into solid-state diffusion in alloys of the Platinum Group Metals (PGMs). Thereby, we pave the way for tailor making surface compositions of binary platinum (Pt) – rhodium (Rh) model catalysts, with deposited rhodium layers on the surface of Pt single crystals (SCs) as the starting point. Platinum single crystals with (100), (110) and (111) orientations were studied by scanning electron microscopy (SEM) and energy dispersive X – ray spectroscopy (EDS). In addition, X – ray Photoelectron spectroscopy (XPS) characterization was carried out on Pt(110). The crystallographic orientation has a prominent effect on diffusion characteristics. The slowest moving Kirkendall – plane was observed for Pt(110) at xK = 250nm from reference point x0, while, the fastest for Pt(100) was at xK = 450nm, indicating that the inter-diffusion rate with respect to orientation increases in the sequence Pt(110)