Irreversible structural dynamics on the surface of bimetallic PtNi alloy catalyst under alternating oxidizing and reducing environments

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F20%3A10422682" target="_blank" >RIV/00216208:11320/20:10422682 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=cPecEejN7D" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=cPecEejN7D</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.apcatb.2019.118476" target="_blank" >10.1016/j.apcatb.2019.118476</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Irreversible structural dynamics on the surface of bimetallic PtNi alloy catalyst under alternating oxidizing and reducing environments

Popis výsledku v původním jazyce

In this work changes in surface chemistry and morphology of PtNi alloy induced by redox environments were investigated by photoelectron spectroscopy, atomic force microscopy and substantiated by theoretical calculations. PtNi was exposed to alternating oxidation (O-2) and reduction (H-2) gaseous atmospheres at different temperatures (298, 373, 523 K) to simulate its behavior as a cathode catalyst in proton exchange membrane fuel cells. Results showed that the PtNi alloy undergoes surface nickel enrichment under switched reactive environments. The most significant effects occurred at 523 K, when the Ni/Pt surface atomic ratio increased from 0.8 to 6.7 after five redox cycles, while the bulk Ni/Pt value reached 2.3. Along with compositional changes catalyst coarsening was observed. The revealed behavior of the PtNi alloy allows a better understanding of the structural dynamics of a bimetallic catalyst during its interaction with reactive environments that is a prerequisite for development of efficient fuel cell catalyst.

Název v anglickém jazyce

Irreversible structural dynamics on the surface of bimetallic PtNi alloy catalyst under alternating oxidizing and reducing environments

Popis výsledku anglicky

In this work changes in surface chemistry and morphology of PtNi alloy induced by redox environments were investigated by photoelectron spectroscopy, atomic force microscopy and substantiated by theoretical calculations. PtNi was exposed to alternating oxidation (O-2) and reduction (H-2) gaseous atmospheres at different temperatures (298, 373, 523 K) to simulate its behavior as a cathode catalyst in proton exchange membrane fuel cells. Results showed that the PtNi alloy undergoes surface nickel enrichment under switched reactive environments. The most significant effects occurred at 523 K, when the Ni/Pt surface atomic ratio increased from 0.8 to 6.7 after five redox cycles, while the bulk Ni/Pt value reached 2.3. Along with compositional changes catalyst coarsening was observed. The revealed behavior of the PtNi alloy allows a better understanding of the structural dynamics of a bimetallic catalyst during its interaction with reactive environments that is a prerequisite for development of efficient fuel cell catalyst.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

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

Applied Catalysis B: Environmental

ISSN

0926-3373

e-ISSN

—

Svazek periodika

264

Číslo periodika v rámci svazku

May

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

9

Strana od-do

118476

Kód UT WoS článku

000515195200012

EID výsledku v databázi Scopus

2-s2.0-85076251395