Understanding the Kinetics and Mechanisms of the Desired and Undesired Reactions during Electrochemical Hydrogenation and Hydrogenolysis of Furfural on Copper in Acidic Media
The decarbonization of the chemical industry would have an immense impact on lowering greenhouse gas emissions and assisting in mitigating global warming. To achieve this there is a growing interest in implementing renewable feedstocks like biomass and coupling of chemical processes with renewable energy. Furfural is a biomass derived species that has been identified as a platform molecule. Electrochemical processes are more easily coupled with renewable electricity and can be used to valorize biomass derived species such as furfural. The installation of electrochemical processes is hindered by a smaller knowledge base compared to thermochemical processes. This dissertation investigates the electrochemical hydrogenation and hydrogenolysis of furfural on copper electrodes in acidic media to better understand the kinetics and mechanisms of the process. Two products are formed, furfuryl alcohol and 2-methylfuran. Furfuryl alcohol is used to produce resins for the foundry industry and 2-methylfuran has been identified as a high-octane fuel. Mathematical models were developed which showed that furfuryl alcohol and 2-methylfuran were produced through non-competitive Langmuir-Hinshelwood mechanisms through different intermediate species from each other. The model was then combined with the kinetics of non-electrochemical side reactions to show how the mass balance is impacted over long durations of electrolysis. While the model captured the trends of the furanic products quite well, further work was needed to capture vi the mass balance losses. Conditions were selected to study the fouling and deactivation of the copper electrodes in acid. In these accelerated fouling conditions, a coke or polymer product was formed, dependent on the applied potential. The polymer formed was poly(furfuryl alcohol), and the coking resembled soot. Poly(furfuryl alcohol) can be targeted as a valorized product of furfural electroreduction, however coking is detrimental to reaction rates and in not otherwise a useful product.
Furfural, Electrochemical Engineering, Hydrogenation, Hydrogenolysis, Kinetics, Catalysis and Reaction Engineering
City University of New York - City College
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