In Situ Stress and Nanogravimetric Measurements During Underpotential Deposition of Pd on (111)-Textured Au.

Published

December 10, 2008

Author(s)

Gery R. Stafford, Ugo Bertocci

Abstract

The surface stress associated with the electrodeposition of Pd onto (111)-textured Au cantilever electrodes in 0.1 M H2SO4 supporting electrolyte has been examined. An electrochemical quartz crystal nanobalance (EQNB) was also used in order to correlate the stress development with the Pd coverage. PdSO4 and H2PdCl4 were separately examined as electroactive species, in order to determine the influence of [PdCl4]2- adsorption on the stress response. The stress associated with Pd upd, as well as with the growth of subsequent adlayers, is tensile, whose primary source is the +4.9 % lattice mismatch between Pd and Au. However the expected tensile stress is in part counterbalanced by the formation of Pd-Au bonds as well as anion adsorption onto the Pd surface. Pd upd causes a surface stress change of +0.4 N m-1 whereas a second monolayer produces an additional stress change of +0.6 N m-1. We attribute this larger tensile stress change for the second monolayer to the diminished electronic influence of the Au substrate. A similar stress response is observed for both H2PdCl4 and PdSO4 as sources of Pd2+.

Citation

Journal of Physical Chemistry

Pub Type

Journals

Citation

Stafford, G. and Bertocci, U. (2008), In Situ Stress and Nanogravimetric Measurements During Underpotential Deposition of Pd on (111)-Textured Au., Journal of Physical Chemistry (Accessed October 11, 2024)