Characterization of solid Lewis acids in biomass conversion reactions.

摘要

Solid Lewis acids can be very selective in many important biomass reactions. Unfortunately, our understanding of solid Lewis acidity is very poor, making it difficult to design and select specific catalysts for a particular reaction. In this dissertation, characterization and examination of solid Lewis acids were performed through home-built instruments including Temperature-Programmed Desorption (TPD)/Thermogravimetric Analysis (TGA), calorimetry, and a multiphase continuous flow reactor. A number of important catalyst families were examined in this work, including bulk metal oxides, ion-exchanged zeolites and framework substitution Lewis acid zeolites. In this work, it has been shown that the adsorption features obtained from TPD-TGA, calorimetry experiments are very helpful in understanding reaction results from reactor study. Adsorption studies are able to determine Lewis site density, relative adsorption strength and activation energy of monomolecular reactions which are extremely valuable information for catalysts. Biomass reactions over Lewis acid catalysts are through multiple and complicated steps. Works in my study provides a valuable method to understand solid Lewis acidity in biomass reactions through an adsorption feature investigation.