Faculty Advisor

Moser, William R.

Abstract

A new catalyst synthesis method, based on hydrodynamic cavitation, was examined for the fabrication of nanostructured catalysts for hydrodesulfurization processing. It was shown that smaller nanoparticles have higher surface/bulk atom ratios. The free energy of the surface atoms of the nanoparticles is higher than atoms in the bulk. As a result, nanoparticles have higher surface energy, which manifests itself in the form of significant effects upon macroproperties such as catalytic activity. The objective of this research was to determine whether the generation of metal support catalysts using Controlled Flow Cavitation techniques could produce high phase purity and controllable nanostructured metal particles. A preliminary catalytic reactivity test was determined for a few of the generated catalysts. The simplicity and versatility of mechanically generated hydrodynamic cavitation was used to synthesize a series of nanostructured cobalt molybdenum oxides on aluminia and cabosil. The goal of these syntheses was to evaluate novel hydrodynamic cavitation synthesis equipment ability to produce high phase purity and control nanostructured materials. Cobalt molybdate catalysts generated using hydrodynamic cavitation technique have greater phase purity than catalysts produced using the classical co-precipitant method. However, there was no definitive conclusion on the ability of the new hydrodynamic cavitation to systematically control the grain size of the cobalt molybdate catalysts and point out that higher-pressure regime are needed to obtain systematic variation of nanometer grain sizes. Catalytic investigation of these catalysts was examined using a lab scale autoclave. Unfortunately, only two hydrodesulfurization (HDS) experiments were completed due to time constraints. These preliminary results indicated little differences in catalytic reactivity; however, the hydrodynamic cavitation catalysts resulted in modest selectivity improvement to biphenyl.

Publisher

Worcester Polytechnic Institute

Date Accepted

January 2000

Major

Chemical Engineering

Project Type

Major Qualifying Project

Accessibility

Restricted-WPI community only

Advisor Department

Chemical Engineering

Advisor Program

Chemical Engineering

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