Transmission Electron Microscopy (TEM) Study of Polycrystalline Ru:Ag/Alumina Supported Catalyst System.

Authors: S. Tajammul HUSSAIN

Abstract: Transmission Electron Microscopy (TEM) was used to characterize bimetallic Ru/Ag Catalyst samples dispersed on a high surface area Alumina support. The addition of Ag increases the metal dispersion but no consistent trend is observed. Ag forms crystallites of various shape and sizes, some of them are present in the close vicinity of Ru but not forming Ru:Ag bimetallics. A part of Ag crystallites cover the Ru surface hence blocking Ru emission. These irregular shaped crystallites are possibly responsible for the increase in metal dispersion. Particles below 2.5 nm were Ag particles, between 2.5 to 5.0 nm were Ru:Ag mixed crystallites and above that were Ru particles. The data has been discussed in terms of geometric effect caused by the addition of Ag.


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