Date of Award

Fall 12-15-2023

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Advisor

Brian Frederick

Second Committee Member

Thomas Schwartz

Third Committee Member

Francois Amar

Abstract

A bimetallic nanoparticle catalyst combines two different metals on an oxide support, which can increase the selectivity towards useful products that may be too tightly bound to a monometallic catalyst. To explore the surface properties of such a system, we made a group of four PdAu bimetallic catalysts with varying gold mass loadings to compare with a parent Pd catalyst. The parent catalyst was synthesized using ion exchange, and gold was added to this parent Pd catalyst using incipient wetness impregnation (IWI) to create four bimetallic catalysts. All catalysts were characterized using H2 and CO chemisorption in tandem with O2 and H2 titration methods. The measured dispersion of the parent catalyst ranged from 60-72% which is consistent with previous measurements for catalysts synthesized with the same loading and synthesis technique. This dispersion value implies an average Pd particle diameter of about 1.8 nm. Each bimetallic catalyst was characterized using chemisorption and titration methods and the fractional gold coverage was found to be about 70%, independent of the gold loading. In parallel with the chemisorption and titration measurements, we used ICP-OES analysis to determine the gold content in the bimetallic catalysts, but these results were inconsistent with the quantities of gold used in the IWI synthesis.

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