Underpotential Co-Deposition of Cu_subscript(1-x)Pt_subscript(x) Alloys

Published

September 30, 2006

Author(s)

J Mallett, Ugo Bertocci, Erik B. Svedberg, John E. Bonevich, Alexander J. Shapiro, William F. Egelhoff Jr., Thomas P. Moffat

Abstract

The electrodeposition of Cu_subscript (1-x)Pt_subscript(x) alloys by underpotential co-deposition of Cu with Pt is demonstrated using an H_subscript(2)SO_subscript(4)-CuSO_subscript(4-)PtCl_subscript(4)_superscript(2-) electrolyte. The composition and structure of 1 microns thick alloy films grown at different potentials were examined by EDS, XRD and TEM. A thermodynamic rational for the alloying process is provided bu a symmetrical regular solution model whereby underpotential co-deposition of Cu is ascribed to the negative enthalpy of mixing with Pt. The observed dependence of alloy composition on potential is in good agreement with equiatomic mixing enthalpy of -18 kJ/mol, obtained from calculations by Miedema et al. An EQCM was used to provide a time resolved assessment of the alloy formation process. Simultaneous measurement of the mass and current transients during potential steps enable the effects of submonolayer underpotential deposition of Cu onto a Pt rich surface to be observed and separated from the subsequent steady-state co-deposition of Cu with Pt.

Proceedings Title

ECS Meeting | 209th | | ECS

Conference Dates

May 7-12, 2006

Conference Title

ECS Meeting Proceedings

Pub Type

Conferences

Keywords

co-deposition, electrodeposition, underpotential

Citation

Mallett, J. , Bertocci, U. , Svedberg, E. , Bonevich, J. , Shapiro, A. , Egelhoff, W. and Moffat, T. (2006), Underpotential Co-Deposition of Cu_subscript(1-x)Pt_subscript(x) Alloys, ECS Meeting | 209th | | ECS (Accessed April 26, 2024)