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Title: Dynamics of electrochemical Pt dissolution at atomic and molecular levels

Understanding and controlling electrochemical interfaces at atomic and molecular levels have transformed electrochemistry into a science with clearly defined fundamental principles leading to significant impact on various electrochemical systems and devices. Although the principles guiding the activity of electrochemical reactions are quite well established, the driving forces that control stability are still poorly understood. Here we utilize in situ monitoring of the early stages of Pt dissolution using the stationary probe rotating disk electrode technique coupled to inductively coupled plasma mass spectrometry (SPRDE-ICPMS). Our unique SPRDE-ICPMS method provides picogram sensitivity levels that, in combination with STM, provide otherwise inaccessible information about the dissolution and redeposition of Pt(111) in acidic environments. We propose two distinct dissolution mechanisms that are active during oxide formation and subsequent oxide reduction. Whereas an electrochemical dissolution mechanism is observed during anodic Pt dissolution (Pt→Pt 2++2e -), a combination of electrochemical (PtO*+2H ++2e -→Pt 0+H 2O) and chemical (PtO*+2H +→Pt 2++H 2O) steps control the dissolution of Pt during the cathodic scan. The redeposition of Pt (Pt 2++2e -→Pt) observed on the cathodic scan is controlled by a delicate balance between the diffusion of Pt 2+ from the double layer and redeposition of Pt 2+ on Ptmore » oxide-free sites.« less
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [3] ;  [1] ;  [1]
  1. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division
  2. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division; Univ. of Sao Paulo (Brazil). Inst. de Quimica de Sao Carlos
  3. Univ. of Sao Paulo (Brazil). Inst. de Quimica de Sao Carlos
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Journal of Electroanalytical Chemistry
Additional Journal Information:
Journal Volume: 819; Journal Issue: C; Journal ID: ISSN 1572-6657
Publisher:
Elsevier
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Fuel Cell Technologies Office (EE-3F); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Dissolution mechanism; Dynamics of dissolution; Oxide formation/reduction; Pt redeposition kinetics; Pt single-crystals; Structure-Stability relationships
OSTI Identifier:
1459887

Lopes, Pietro P., Tripkovic, Dusan, Martins, Pedro F. B. D., Strmcnik, Dusan, Ticianelli, Edson A., Stamenkovic, Vojislav R., and Markovic, Nenad M.. Dynamics of electrochemical Pt dissolution at atomic and molecular levels. United States: N. p., Web. doi:10.1016/j.jelechem.2017.09.047.
Lopes, Pietro P., Tripkovic, Dusan, Martins, Pedro F. B. D., Strmcnik, Dusan, Ticianelli, Edson A., Stamenkovic, Vojislav R., & Markovic, Nenad M.. Dynamics of electrochemical Pt dissolution at atomic and molecular levels. United States. doi:10.1016/j.jelechem.2017.09.047.
Lopes, Pietro P., Tripkovic, Dusan, Martins, Pedro F. B. D., Strmcnik, Dusan, Ticianelli, Edson A., Stamenkovic, Vojislav R., and Markovic, Nenad M.. 2017. "Dynamics of electrochemical Pt dissolution at atomic and molecular levels". United States. doi:10.1016/j.jelechem.2017.09.047. https://www.osti.gov/servlets/purl/1459887.
@article{osti_1459887,
title = {Dynamics of electrochemical Pt dissolution at atomic and molecular levels},
author = {Lopes, Pietro P. and Tripkovic, Dusan and Martins, Pedro F. B. D. and Strmcnik, Dusan and Ticianelli, Edson A. and Stamenkovic, Vojislav R. and Markovic, Nenad M.},
abstractNote = {Understanding and controlling electrochemical interfaces at atomic and molecular levels have transformed electrochemistry into a science with clearly defined fundamental principles leading to significant impact on various electrochemical systems and devices. Although the principles guiding the activity of electrochemical reactions are quite well established, the driving forces that control stability are still poorly understood. Here we utilize in situ monitoring of the early stages of Pt dissolution using the stationary probe rotating disk electrode technique coupled to inductively coupled plasma mass spectrometry (SPRDE-ICPMS). Our unique SPRDE-ICPMS method provides picogram sensitivity levels that, in combination with STM, provide otherwise inaccessible information about the dissolution and redeposition of Pt(111) in acidic environments. We propose two distinct dissolution mechanisms that are active during oxide formation and subsequent oxide reduction. Whereas an electrochemical dissolution mechanism is observed during anodic Pt dissolution (Pt→Pt2++2e-), a combination of electrochemical (PtO*+2H++2e-→Pt0+H2O) and chemical (PtO*+2H+→Pt2++H2O) steps control the dissolution of Pt during the cathodic scan. The redeposition of Pt (Pt2++2e-→Pt) observed on the cathodic scan is controlled by a delicate balance between the diffusion of Pt2+ from the double layer and redeposition of Pt2+ on Pt oxide-free sites.},
doi = {10.1016/j.jelechem.2017.09.047},
journal = {Journal of Electroanalytical Chemistry},
number = C,
volume = 819,
place = {United States},
year = {2017},
month = {9}
}