Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Role of Elastic Strain on Electrocatalysis of Oxygen Reduction Reaction on Pt

Published

Author(s)

Gery R. Stafford, Vijay Sethuraman, Deepa Vairavapandian, Manon C. Lafouresse, Tuhina Maark, Naba Karan, Shouheng Sun, Ugo Bertocci, Andrew Peterson, Pradeep Guduru

Abstract

The effect of elastic strain on catalytic activity of platinum (Pt) towards oxygen reduction reaction (ORR) is investigated through de-alloyed Pt-Cu thin films; stress evolution in the de-alloyed layer and the mass of the Cu removed are measured in real-time during electrochemical de-alloying of (111)-textured thin-film PtCu electrodes. In situ stress measurements are made using the cantilever-deflection method and nano-gravimetric measurements are made using an electrochemical quartz crystal nanobalance. Upon de-alloying via successive voltammetric sweeps between -0.05 and 1.15 V vs. standard hydrogen electrode, compressive stress develops in the de-alloyed Pt layer at the surface of thin-film PtCu electrodes. The de-alloyed films also exhibit enhanced catalytic activity towards ORR compared to polycrystalline Pt. In situ nanogravimetric measurements reveal that the mass of de- alloyed Cu is approximately 210 ± 46 ng/cm2, which corresponds to a de-alloyed layer thickness of 1.2 ± 0.3 monolayers or 0.16 ± 0.04 nm. The average biaxial stress in the de-alloyed layer is estimated to be 4.95 ± 1.3 GPa, which corresponds to an elastic strain of 1.47 ± 0.4%. In addition, density functional theory calculations have been carried out on biaxially strained Pt (111) surface to characterize the effect of strain on its ORR activity; the predicted shift in the limiting potentials due to elastic strain is found to be in good agreement with the experimental shift in the cyclic voltammograms for the dealloyed PtCu thin film electrodes.
Citation
Journal of Physical Chemistry C

Keywords

electrocatalysis, strain, de-alloying, Pt alloys

Citation

Stafford, G. , Sethuraman, V. , Vairavapandian, D. , Lafouresse, M. , Maark, T. , Karan, N. , Sun, S. , Bertocci, U. , Peterson, A. and Guduru, P. (2015), Role of Elastic Strain on Electrocatalysis of Oxygen Reduction Reaction on Pt, Journal of Physical Chemistry C (Accessed May 22, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created July 23, 2015, Updated March 22, 2017