Reduction of Pd2+ pre-adsorbed on cyanide-modified Pt(111) electrodes

adlayer metallization vs. metal-on-metal deposition

Jonathan A. Mwanda, Angel Cuesta (Corresponding Author)

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

We have studied the reduction of Pd2+ irreversibly and non-covalently immobilized on a cyanide modified Pt (111) electrode using cyclic voltammetry (CV) and in-situ scanning tunnelling microscopy (STM). Contrary to Cu2+, the reduction of which results in the metallisation of the cyanide adlayer (J. Solid State Electrochem. 20 (2015) 1087–1094), reduction of Pd2+ results on the deposition on the Pt(111) substrate of Pd triangular nanoislands containing approximately 30 atoms in average and evenly distributed over the electrode surface. A potential excursion below 0.20 V vs. RHE results in the islands swelling and increasing their surface. This swelling effect is size-dependent, and while the smaller islands increase their area by as much as 60-75% within the hydrogen region, bigger islands swell by just 12%. We attribute this effect to hydrogen absorption within the palladium islands, which also increases the mobility of the Pd atoms and leads to the formation of larger islands. Cyclic voltammetry suggests that repeated cycling into the hydrogen evolution region results in an increase in the size of epitaxial Pd bidimensional is;lands on Pt(111), which is consistent with the evolution observed using STM.
Original languageEnglish
Pages (from-to)419-424
Number of pages6
JournalElectrochimica Acta
Volume292
Early online date26 Sep 2018
DOIs
Publication statusPublished - 1 Dec 2018

Fingerprint

Cyanides
Metallizing
Hydrogen
Metals
Scanning tunneling microscopy
Electrodes
Cyclic voltammetry
Swelling
Atoms
Palladium
Substrates

Keywords

  • cyanide-modified Pt(111)
  • electrodeposition
  • Pd
  • in-situ STM
  • cyclic voltammetry

Cite this

@article{4ecd2edc16a9418b9161e5d082febe3c,
title = "Reduction of Pd2+ pre-adsorbed on cyanide-modified Pt(111) electrodes: adlayer metallization vs. metal-on-metal deposition",
abstract = "We have studied the reduction of Pd2+ irreversibly and non-covalently immobilized on a cyanide modified Pt (111) electrode using cyclic voltammetry (CV) and in-situ scanning tunnelling microscopy (STM). Contrary to Cu2+, the reduction of which results in the metallisation of the cyanide adlayer (J. Solid State Electrochem. 20 (2015) 1087–1094), reduction of Pd2+ results on the deposition on the Pt(111) substrate of Pd triangular nanoislands containing approximately 30 atoms in average and evenly distributed over the electrode surface. A potential excursion below 0.20 V vs. RHE results in the islands swelling and increasing their surface. This swelling effect is size-dependent, and while the smaller islands increase their area by as much as 60-75{\%} within the hydrogen region, bigger islands swell by just 12{\%}. We attribute this effect to hydrogen absorption within the palladium islands, which also increases the mobility of the Pd atoms and leads to the formation of larger islands. Cyclic voltammetry suggests that repeated cycling into the hydrogen evolution region results in an increase in the size of epitaxial Pd bidimensional is;lands on Pt(111), which is consistent with the evolution observed using STM.",
keywords = "cyanide-modified Pt(111), electrodeposition, Pd, in-situ STM, cyclic voltammetry",
author = "Mwanda, {Jonathan A.} and Angel Cuesta",
note = "Acknowledgement The support of the University of Aberdeen is gratefully acknowledged.",
year = "2018",
month = "12",
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doi = "10.1016/j.electacta.2018.08.120",
language = "English",
volume = "292",
pages = "419--424",
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TY - JOUR

T1 - Reduction of Pd2+ pre-adsorbed on cyanide-modified Pt(111) electrodes

T2 - adlayer metallization vs. metal-on-metal deposition

AU - Mwanda, Jonathan A.

AU - Cuesta, Angel

N1 - Acknowledgement The support of the University of Aberdeen is gratefully acknowledged.

PY - 2018/12/1

Y1 - 2018/12/1

N2 - We have studied the reduction of Pd2+ irreversibly and non-covalently immobilized on a cyanide modified Pt (111) electrode using cyclic voltammetry (CV) and in-situ scanning tunnelling microscopy (STM). Contrary to Cu2+, the reduction of which results in the metallisation of the cyanide adlayer (J. Solid State Electrochem. 20 (2015) 1087–1094), reduction of Pd2+ results on the deposition on the Pt(111) substrate of Pd triangular nanoislands containing approximately 30 atoms in average and evenly distributed over the electrode surface. A potential excursion below 0.20 V vs. RHE results in the islands swelling and increasing their surface. This swelling effect is size-dependent, and while the smaller islands increase their area by as much as 60-75% within the hydrogen region, bigger islands swell by just 12%. We attribute this effect to hydrogen absorption within the palladium islands, which also increases the mobility of the Pd atoms and leads to the formation of larger islands. Cyclic voltammetry suggests that repeated cycling into the hydrogen evolution region results in an increase in the size of epitaxial Pd bidimensional is;lands on Pt(111), which is consistent with the evolution observed using STM.

AB - We have studied the reduction of Pd2+ irreversibly and non-covalently immobilized on a cyanide modified Pt (111) electrode using cyclic voltammetry (CV) and in-situ scanning tunnelling microscopy (STM). Contrary to Cu2+, the reduction of which results in the metallisation of the cyanide adlayer (J. Solid State Electrochem. 20 (2015) 1087–1094), reduction of Pd2+ results on the deposition on the Pt(111) substrate of Pd triangular nanoislands containing approximately 30 atoms in average and evenly distributed over the electrode surface. A potential excursion below 0.20 V vs. RHE results in the islands swelling and increasing their surface. This swelling effect is size-dependent, and while the smaller islands increase their area by as much as 60-75% within the hydrogen region, bigger islands swell by just 12%. We attribute this effect to hydrogen absorption within the palladium islands, which also increases the mobility of the Pd atoms and leads to the formation of larger islands. Cyclic voltammetry suggests that repeated cycling into the hydrogen evolution region results in an increase in the size of epitaxial Pd bidimensional is;lands on Pt(111), which is consistent with the evolution observed using STM.

KW - cyanide-modified Pt(111)

KW - electrodeposition

KW - Pd

KW - in-situ STM

KW - cyclic voltammetry

UR - https://www.sciencedirect.com/science/article/pii/S0013468618318747

U2 - 10.1016/j.electacta.2018.08.120

DO - 10.1016/j.electacta.2018.08.120

M3 - Article

VL - 292

SP - 419

EP - 424

JO - Electrochimica Acta

JF - Electrochimica Acta

SN - 0013-4686

ER -