Titre du document / Document title

Electrocatalytic oxidation of formaldehyde on gold studied by differential electrochemical mass spectrometry and voltammetry

Auteur(s) / Author(s)

TEN KORTENAAR M. V. ^{(1 2)} ; KOLAR Z. I. ⁽¹⁾ ; DE GOEIJ J. J. M. ⁽¹⁾ ; FRENS G. ⁽²⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Department of Radiochemistry, Interfaculty Reactor Institute, Faculty of Applied Sciences, Delft University of Technology, 2628 BL Delft, PAYS-BAS
⁽²⁾ Laboratory of Physical Chemistry, Faculty of Applied Sciences, Delft University of Technology, 2628 BL Delft, PAYS-BAS

Résumé / Abstract

The electrocatalytic oxidation of normal formaldehyde I CH₂O) and deuterated formaldehyde (CD₂O) has been studied on gold in aqueous, alkaline solution as a function of pH, concentration, potential, and temperature by voltammetry, chronoamperometry, and differential electrochemical mass spectrometry. The H₂. D₂. and CO₂ gas evolution kinetics depend to great extent on the pH, potential, and temperature but play a minor role in the overall rate of the electro-oxidation reaction. The evolution of hydrogen at the open-circuit potential and the current efficiencies larger than 100% pointed toward the occurrence of a nonelectrochemical dehydrogenation reaction parallel to the electro-oxidation reaction, The kinetic isotope effects and activation energies suggested that the overall rate of the electro-oxidation reaction is determined by the hydroxyl catalyzed, enthalpy-driven, chemisorption of the enolate anion at low potentials, by the entropy-driven desorption of the formate anion at higher potentials, and by diffusion at the highest potentials. The apparent activation energies (E_a) ranged in value between -25 and 60 kJ mol ¹ confirming the highly catalytic properties of gold in the overall rate of the reaction.

Revue / Journal Title

Journal of the Electrochemical Society   ISSN 0013-4651   CODEN JESOAN 

Source / Source

2001, vol. 148, n^o8, pp. E327-E335 (32 ref.)

Langue / Language

Anglais

Editeur / Publisher

Electrochemical Society, Pennington, NJ, ETATS-UNIS  (1948) (Revue)

Mots-clés anglais / English Keywords

Experimental study ; Oxidation ; Electrochemical reaction ; Formaldehyde ; Aldehyde ; Disk electrode ; Gold ; Polycrystal ; Noble metal ; Mass spectrometry ; Electrocatalysis ; Basic solution ; Sodium Hydroxides ; Transition metal ;

Mots-clés français / French Keywords

Etude expérimentale ; Oxydation ; Réaction électrochimique ; Formaldéhyde ; Aldéhyde ; Electrode disque ; Or ; Polycristal ; Métal noble ; Spectrométrie masse ; Electrocatalyse ; Solution basique ; Sodium Hydroxyde ; Métal transition ;

Mots-clés espagnols / Spanish Keywords

Estudio experimental ; Oxidación ; Reacción electroquímica ; Formaldehído ; Aldehído ; Electrodo disco ; Oro ; Policristal ; Metal noble ; Espectrometría masa ; Electrocatálisis ; Solución básica ; Sodio Hidróxido ; Metal transición ;

Localisation / Location

INIST-CNRS, Cote INIST : 4925, 35400009716441.0390