Ultraviolet-visible (UV-vis) spectroscopy is a powerful, common, and affordable technique for the characterization of heterogeneous catalysts. Here we present an improved design of a commercial Harrick Scientific high temperature reaction chamber for use with a diffuse reflectance (DR) optical fiber probe. A metallic dome was designed to fit with the reaction chamber and to hold a laboratory grade diffuse reflectance optical fiber probe in direct proximity (a couple of mm) of the surface of the catalyst sample. The new design allows rapid acquisition (within seconds) of UV-vis spectra at temperatures above 800 <sup>o</sup>C and pressures beyond the manufacturer’s limit of 15 bar. This improved simple microreactor setup is particularly useful for kinetic measurements of adsorption, surface reaction, and desorption of reactants and products on catalyst surfaces with characteristic fingerprints in the UV-vis region. In this presentation, we will discuss some of our results of in situ DR-UV-vis spectroscopy to determine adsorption kinetics of oxidizing and reducing probe molecules on the surface of various supported gold catalysts. We will also show how gold plasmon peak shifts can be used to characterize gold-support interactions.

Improved design of a commercial, diffuse reflectance reactor for <i>in-situ</i>, ultraviolet-visible spectroscopy studies

251st National Meeting (2016)

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Improved design of a commercial, diffuse reflectance reactor for in-situ, ultraviolet-visible spectroscopy studies