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.