Application of Potassium Ion Deposition in Determining the Impact of Support Reducibility on Catalytic Activity of Au/Ceria-Zirconia Catalysts in CO Oxidation, NO Oxidation, and C3H8 Combustion

Ewa M. Iwanek (nee Wilczkowska) , Leonarda F. Liotta , Shazam Williams , Linjie Hu , Krishelle Calilung , Giuseppe Pantaleo , Zbigniew Kaszkur , Donald W. Kirk , Marek Gliński

Abstract

The purpose of the study was to show how a controlled, subtle change of the reducibility of the support by deposition of potassium ions impacts the activity of gold catalysts. Since the activity of supported gold catalysts in carbon monoxide oxidation is known to strongly depend on the reducibility of the support, this reaction was chosen as the model reaction. The results of tests conducted in a simple system in which the only reagents were CO and O2 showed good agreement with the CO activity trend in tests performed in a complex stream of reagents, which also contained CH4, C2H6, C3H8, NO, and water vapor. The results of the X-ray Diffraction (XRD) studies revealed that the support has the composition Ce0.85Zr0.15O2, that its lattice constant is the same for all samples, and that gold is mostly present in the metallic phase. The reducibility of the systems was established based on Temperature Programmed Reduction (TPR) and in situ XRD measurements in H2 atmosphere. The results show that the low temperature reduction peak, which is due to the presence of gold, is shifted to a higher value by the presence of 0.3 at% potassium ions on the surface. Moreover, the increase of the potassium loading leads to a more pronounced shift. The T50 of CO oxidation in the simple model stream was found to exhibit an excellent linear correlation with the maximum temperature of the low temperature reduction peak of Au catalysts. This means that stabilizing oxygen with a known amount of potassium ions can be numerically used to estimate the T50 in CO oxidation. The results in the complex stream also showed a similar dependence of CO conversion on reducibility, though there was no substantial difference in the activity of the catalysts in other reactions regardless of the potassium loading. These studies have shown that the influence of potassium varies depending on the reaction, which highlights differences in the impact of reducibility and importance of other factors in these reactions.
Author Ewa M. Iwanek (nee Wilczkowska)
Ewa M. Iwanek (nee Wilczkowska),,
-
, Leonarda F. Liotta
Leonarda F. Liotta,,
-
, Shazam Williams
Shazam Williams,,
-
, Linjie Hu
Linjie Hu,,
-
, Krishelle Calilung
Krishelle Calilung,,
-
, Giuseppe Pantaleo
Giuseppe Pantaleo,,
-
, Zbigniew Kaszkur
Zbigniew Kaszkur,,
-
, Donald W. Kirk
Donald W. Kirk,,
-
, Marek Gliński (FC / CChT)
Marek Gliński,,
- Chair of Chemical Technology
Journal seriesCatalysts, ISSN 2073-4344
Issue year2020
Vol10
No6
Pages1-13
Publication size in sheets0.6
Article number688
Keywords in EnglishCO oxidation, potassium poisoning, gold nanoparticles, ceria-zirconia, NO oxidation, propane combustion
ASJC Classification1503 Catalysis; 1606 Physical and Theoretical Chemistry
DOIDOI:10.3390/catal10060688
URL https://www.mdpi.com/2073-4344/10/6/688
Languageen angielski
Score (nominal)100
Score sourcejournalList
ScoreMinisterial score = 100.0, 22-07-2020, ArticleFromJournal
Publication indicators Scopus SNIP (Source Normalised Impact per Paper): 2018 = 0.912; WoS Impact Factor: 2018 = 3.444 (2) - 2018=3.808 (5)
Citation count*
Cite
Share Share

Get link to the record


* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.
Back
Confirmation
Are you sure?