Direct determination of equilibrium potentials for hydrogen oxidation/production by open circuit potential measurements in acetonitrile

Research output: Contribution to journalArticle

86 Citations (Scopus)

Abstract

Open circuit potentials were measured for acetonitrile solutions of a variety of acids and their conjugate bases under 1 atm H2. Acids examined were triethylammonium, dimethylformamidium, 2,6-dichloroanilinium, 4-cyanoanilinium, 4-bromoanilinium, and 4-anisidinium salts. These potentials, along with the pKa values of the acids, establish the value of the standard hydrogen electrode (SHE) potential in acetonitrile as -0.028(4) V vs the ferrocenium/ferrocene couple. Dimethylformamidium forms homoconjugates and other aggregates with dimethylformamide; open circuit potentials (OCPs) were used to quantify the extent of these reactions. Overpotentials for electrocatalytic hydrogen production and oxidation were determined from open circuit potentials and voltammograms of acidic or basic catalyst solutions under H2. For these solutions, agreement between OCP values and potentials calculated using the Nernst equation is within 12 mV. Use of the measured equilibrium potential allows direct comparison of catalytic systems in different media; it requires neither pKa values, homoconjugation constants, nor the SHE potential.

Original languageEnglish
Pages (from-to)3823-3835
Number of pages13
JournalInorganic Chemistry
Volume52
Issue number7
DOIs
Publication statusPublished - Apr 1 2013

Fingerprint

acetonitrile
Hydrogen
Oxidation
oxidation
Networks (circuits)
hydrogen
Acids
Dimethylformamide
Electrodes
Hydrogen production
acids
Salts
Catalysts
electrodes
hydrogen production
salts
catalysts

ASJC Scopus subject areas

  • Inorganic Chemistry
  • Physical and Theoretical Chemistry

Cite this

@article{b4b91c74ee2a4907877908cf3ffdb6a5,
title = "Direct determination of equilibrium potentials for hydrogen oxidation/production by open circuit potential measurements in acetonitrile",
abstract = "Open circuit potentials were measured for acetonitrile solutions of a variety of acids and their conjugate bases under 1 atm H2. Acids examined were triethylammonium, dimethylformamidium, 2,6-dichloroanilinium, 4-cyanoanilinium, 4-bromoanilinium, and 4-anisidinium salts. These potentials, along with the pKa values of the acids, establish the value of the standard hydrogen electrode (SHE) potential in acetonitrile as -0.028(4) V vs the ferrocenium/ferrocene couple. Dimethylformamidium forms homoconjugates and other aggregates with dimethylformamide; open circuit potentials (OCPs) were used to quantify the extent of these reactions. Overpotentials for electrocatalytic hydrogen production and oxidation were determined from open circuit potentials and voltammograms of acidic or basic catalyst solutions under H2. For these solutions, agreement between OCP values and potentials calculated using the Nernst equation is within 12 mV. Use of the measured equilibrium potential allows direct comparison of catalytic systems in different media; it requires neither pKa values, homoconjugation constants, nor the SHE potential.",
author = "John Roberts and Bullock, {R Morris}",
year = "2013",
month = "4",
day = "1",
doi = "10.1021/ic302461q",
language = "English",
volume = "52",
pages = "3823--3835",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "7",

}

TY - JOUR

T1 - Direct determination of equilibrium potentials for hydrogen oxidation/production by open circuit potential measurements in acetonitrile

AU - Roberts, John

AU - Bullock, R Morris

PY - 2013/4/1

Y1 - 2013/4/1

N2 - Open circuit potentials were measured for acetonitrile solutions of a variety of acids and their conjugate bases under 1 atm H2. Acids examined were triethylammonium, dimethylformamidium, 2,6-dichloroanilinium, 4-cyanoanilinium, 4-bromoanilinium, and 4-anisidinium salts. These potentials, along with the pKa values of the acids, establish the value of the standard hydrogen electrode (SHE) potential in acetonitrile as -0.028(4) V vs the ferrocenium/ferrocene couple. Dimethylformamidium forms homoconjugates and other aggregates with dimethylformamide; open circuit potentials (OCPs) were used to quantify the extent of these reactions. Overpotentials for electrocatalytic hydrogen production and oxidation were determined from open circuit potentials and voltammograms of acidic or basic catalyst solutions under H2. For these solutions, agreement between OCP values and potentials calculated using the Nernst equation is within 12 mV. Use of the measured equilibrium potential allows direct comparison of catalytic systems in different media; it requires neither pKa values, homoconjugation constants, nor the SHE potential.

AB - Open circuit potentials were measured for acetonitrile solutions of a variety of acids and their conjugate bases under 1 atm H2. Acids examined were triethylammonium, dimethylformamidium, 2,6-dichloroanilinium, 4-cyanoanilinium, 4-bromoanilinium, and 4-anisidinium salts. These potentials, along with the pKa values of the acids, establish the value of the standard hydrogen electrode (SHE) potential in acetonitrile as -0.028(4) V vs the ferrocenium/ferrocene couple. Dimethylformamidium forms homoconjugates and other aggregates with dimethylformamide; open circuit potentials (OCPs) were used to quantify the extent of these reactions. Overpotentials for electrocatalytic hydrogen production and oxidation were determined from open circuit potentials and voltammograms of acidic or basic catalyst solutions under H2. For these solutions, agreement between OCP values and potentials calculated using the Nernst equation is within 12 mV. Use of the measured equilibrium potential allows direct comparison of catalytic systems in different media; it requires neither pKa values, homoconjugation constants, nor the SHE potential.

UR - http://www.scopus.com/inward/record.url?scp=84875789067&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84875789067&partnerID=8YFLogxK

U2 - 10.1021/ic302461q

DO - 10.1021/ic302461q

M3 - Article

VL - 52

SP - 3823

EP - 3835

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 7

ER -