To the mechanism coarsening of Ostwald ripening of Pt, Pd catalysts and their compounds

Autor: I. V. Fesiv, B. V. Ivanskii, V. I. Kryvetskyi, R. D. Vengrenovich, I. I. Panko, M. O. Stasyk
Rok vydání: 2015
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
DOI: 10.1117/12.2224724
Popis: A comparison between the generalized Chakraverty-Wagner and Lifshits-Slyozov-Wagner distributions with experimental histograms for Pt, Pd –nanocrystals and their compounds has been performed according to the modified LSW theory applied to the surface (2D) and bulk (3D) systems. Pt and Pd nanocrystals were synthesized and deposited from vapor phase and a liquid solution. Good correlation between the experimental histograms and the theoretical curves proves that two mechanisms of the nanocrystals’ growth (dissolution) can be involved simultaneously during the Ostwald ripening stage. One of them is controlled by diffusion, while the chemical reaction rate controls the other mechanism. Details of comparison between the experimental histograms and theoretical curves prove that growth of Pt and Pd -nanoparticles is controlled mainly by the chemical reaction rate (i.e. Wagner’s mechanism) regardless of the synthesis method in the process of Ostwald ripening.
Databáze: OpenAIRE