Degradation kinetics of Pt during high-temperature PEM fuel cell operation part II: Dissolution kinetics of Pt incorporated in a catalyst layer of a gas-diffusion electrode

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F20%3A43920517" target="_blank" >RIV/60461373:22310/20:43920517 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.electacta.2019.135509" target="_blank" >https://doi.org/10.1016/j.electacta.2019.135509</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.electacta.2019.135509" target="_blank" >10.1016/j.electacta.2019.135509</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Degradation kinetics of Pt during high-temperature PEM fuel cell operation part II: Dissolution kinetics of Pt incorporated in a catalyst layer of a gas-diffusion electrode

Popis výsledku v původním jazyce

This paper presents the experimentally studied degradation of a gas-diffusion electrode under a potentiostatic regime. The experimental conditions corresponded to the operation of a high-temperature fuel cell with a proton-exchange membrane, e.g. in 99.6 wt% H3PO4, at a temperature of 160 °C. A one-dimensional mathematical model of the degradation of a gas-diffusion electrode was validated using experimental data and utilised for determination of kinetics data of the electrochemical dissolution of Pt. The mathematical model predicted a general mechanism of Pt degradation during electrode polarisation, comprising the electrochemical oxidation of the surface of smaller nanoparticles to PtO, followed by the chemical dissolution of PtO to Pt2+ (sol) and electrochemical reduction of the formed Pt2+ (sol) on the bare Pt surface of larger nanoparticles. The intensity of degradation varied with the electrode polarisation potential. At potentials close to 0.7 V vs. dynamic hydrogen electrode (DHE), only small nanoparticles were dissolved, while at potentials close to 1 V vs. DHE, Pt dissolution took place on a wider range of nanoparticle sizes, resulting in a higher concentration of Pt2+ (sol) on the electrode and, consequently, in a higher rate of nanoparticle growth. The mathematical model presented can be used, with modifications, to make an approximate estimate of the extent of degradation and Pt nanoparticle size distribution in a gas-diffusion cathode, depending on the polarisation potential within the range of 0.7–1 V vs. DHE. © 2019 Elsevier Ltd

Název v anglickém jazyce

Degradation kinetics of Pt during high-temperature PEM fuel cell operation part II: Dissolution kinetics of Pt incorporated in a catalyst layer of a gas-diffusion electrode

Popis výsledku anglicky

This paper presents the experimentally studied degradation of a gas-diffusion electrode under a potentiostatic regime. The experimental conditions corresponded to the operation of a high-temperature fuel cell with a proton-exchange membrane, e.g. in 99.6 wt% H3PO4, at a temperature of 160 °C. A one-dimensional mathematical model of the degradation of a gas-diffusion electrode was validated using experimental data and utilised for determination of kinetics data of the electrochemical dissolution of Pt. The mathematical model predicted a general mechanism of Pt degradation during electrode polarisation, comprising the electrochemical oxidation of the surface of smaller nanoparticles to PtO, followed by the chemical dissolution of PtO to Pt2+ (sol) and electrochemical reduction of the formed Pt2+ (sol) on the bare Pt surface of larger nanoparticles. The intensity of degradation varied with the electrode polarisation potential. At potentials close to 0.7 V vs. dynamic hydrogen electrode (DHE), only small nanoparticles were dissolved, while at potentials close to 1 V vs. DHE, Pt dissolution took place on a wider range of nanoparticle sizes, resulting in a higher concentration of Pt2+ (sol) on the electrode and, consequently, in a higher rate of nanoparticle growth. The mathematical model presented can be used, with modifications, to make an approximate estimate of the extent of degradation and Pt nanoparticle size distribution in a gas-diffusion cathode, depending on the polarisation potential within the range of 0.7–1 V vs. DHE. © 2019 Elsevier Ltd

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10405 - Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Electrochimica Acta

ISSN

0013-4686

e-ISSN

—

Svazek periodika

333

Číslo periodika v rámci svazku

february

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

17

Strana od-do

—

Kód UT WoS článku

000507341600010

EID výsledku v databázi Scopus

2-s2.0-85077333781