Insights into Palladium Deactivation during Advanced Oxidation Processes

• Published in: Chemistry of materials Vol. 34; no. 19; pp. 8760 - 8768
• Main Authors: Pinos-Vélez, Verónica, Osegueda, Oscar, Crivoi, Dana Georgiana, Llorca, Jordi, García-García, F. Javier, Álvarez, Mayra G., Medina, Francesc, Dafinov, Anton
• Format: Journal Article
• Language: English
• Published: American Chemical Society 11-10-2022
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/acs.chemmater.2c01951

A key step in creating efficient and long-lasting catalysts is understanding their deactivation mechanism(s). On this basis, the behavior of a series of Pd/corundum materials during several hydrogen adsorption/desorption cycles was studied using temperature-programmed desorption coupled with mass spectrometry and aberration-corrected transmission electron microscopy. The materials, prepared by impregnation and by sputtering, presented uniform well-dispersed Pd nanoparticles. In addition, single atoms and small clusters of Pd were only detected in the materials prepared by impregnation. Upon exposure to hydrogen, the Pd nanoparticles smaller than 2 nm and the single atoms did not present any change, while the larger ones presented a core–shell morphology, where the core was Pd and the shell was PdH x . The results suggest that the long-term activity of the materials prepared by impregnation can be attributed solely to the presence of small clusters and single atoms of Pd.