Partial phase diagrams of the Dy–Pt and Ho–Pt systems and electrocatalytic behaviour of the DyPt and HoPt phases
作者:D. Macciò、F. Rosalbino、A. Saccone、S. Delfino
DOI:10.1016/j.jallcom.2004.08.050
日期:2005.4
The Dy-Pt and Ho-Pt alloy systems have been investigated in the 0-50 at.% Pt composition range by using differential thermal analysis, metallographic analysis, X-ray powder diffraction and electron probe microanalysis. The R3Pt, R2Pt, R5Pt3, R5Pt4 and RPt intermetallic phases (R = Dy, Ho) have been found and their structures confirmed. All these phases form through peritectic reactions, with the exception of the equiatomic phases DyPt and HoPt melting congruently.The electrocatalytic behaviour of the DyPt and HoPt equiatomic phases towards the hydrogen evolution reaction (her) has been studied by means of cathodic polarization curves and electrochemical impedance measurements, both performed in oxygen-free 1 M NaOH solution at 298 K. The higher catalytic efficiency observed for RPt electrodes compared with pure Pt is explained on the basis of improved three-dimensional hydridic features of composite electrocatalysts. (c) 2004 Elsevier B.V. All rights reserved.