Conversion of Bio-Based Molecules: New Catalytic Approaches
Abstract
The development of catalytic processes for generating bio-based chemicals will
require the emergence of new catalytic systems. Given the excess oxygen
present, acid catalyzed dehydration is an important reaction in producing
bio-based chemicals. The limited volatility of many biobased reactants
necessitates that catalytic systems need to be developed that can operate in the
aqueous phase. Glucose conversion to 5-hydoxymethylfurfural (HMF) using a
combination of Brønsted and Lewis acid catalysts will be discussed in which a
key issue is the balance between Brønsted and Lewis acidity. Water compatible
Lewis acid catalysts such as lanthanide chlorides were utilized to give
respectable yields of HMF while being operated with less Brønsted acid. Ideally,
heterogeneous catalysts could be synthesized for these reactions, however, the
materials would need to be hydrothermally stable. Sulfonated carbons, which
have been proposed as hydrothermally stable solid Brønsted acid catalysts, were
examined under relevant reaction conditions. The stability behavior and
structural characterization via solid state carbon NMR of sulfonated carbons
synthesized using several strategies from carbohydrates will be compared.
Finally, the strategy being developed by CBiRC for creating a general framework
for catalytic systems designed to produce bio-based chemicals, which employs
combined biocatalytic and chemical catalytic systems, will be discussed.