Date of Graduation

5-2019

Document Type

Thesis

Degree Name

Bachelor of Science in Chemical Engineering

Degree Level

Undergraduate

Department

Chemical Engineering

Advisor/Mentor

Kilyanek, Stefan

Committee Member/Reader

Greenlee, Lauren

Abstract

The deoxydehydration (DODH) of polyols to alkenes is a promising method of producing high-value chemical feedstocks from biomass-derived materials. Current catalytic systems for DODH require the use of costly reducing agents that generate stoichiometric amounts of chemical waste. Immobilizing catalysts on electrode surfaces using chemical linking groups eliminates the need for sacrificial reductants. In this work, glassy carbon electrodes were modified with 4’-(3,4-dihydroxyphenyl)-2,2’:6’,2’’-terpyridine to investigate o-benzoquinone as a potential linking group for DODH, and possibly for other reactions. Previous studies involving electrodes modified with quinone-containing compounds have primarily been focused on catalyzing the oxidation of NADH; the nature or stability of the ligand-electrode bond was not the primary focus of interest. In this work, the long-term chemical stability of the modified electrodes was determined in pHs ranging from 0 to 15. The ability of the ligand-electrode bond to withstand potential cycling, as well as periods of time at constant potentials, was established through cyclic voltammetry and chronoamperometry experiments. The goal of this work is to find the windows of chemical and electrochemical stability in which the bond between the quinone moieties and the electrode surface can survive, and to eventually determine the usefulness of this linking group as a means of catalyst immobilization for DODH reactions. From the stability studies performed, it has been shown that the bond between the electrode surface and 4’-(3,4-Dihydroxyphenyl)-2,2’:6’,2"-terpyridine is robust in chemical environments from pH 3.5 to pH 8, and that it can withstand potential cycling and survive for extended time periods at constant potentials, as long as the potential range is more cathodic than 0.2 V vs. Ag/AgCl sat. KCl.

Keywords

electrochemistry; electrode surface modification; cyclic voltammetry; chronoamperometry

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