Biomass Depolymerization projects
Catalytic Conversion and Degradation of Lignocellulosic Materials
Being a polymer composed of many C–O bonds, lignin is optimally degraded by breaking these linkages. In this project, researchers will search for nontraditional methods for the scission of C-O bonds relying on organometallic reactions. The main effort will be aimed at high-risk, high-return fundamental studies of organometallic reactions using well-defined substrates and reagents. New reactions that may prove ineffective for delignification could prove useful in other areas of biofuels and biomaterials. And, most importantly, new chemical principles and new researchers trained in this area represent the ultimate payback, as in any “translational research.”
Rauchfuss’s group discovered new catalysts that break ether bonds of the kind found in lignin. In contrast to known catalysts, the new system based on soluble nickel complexes allows for highly selective cleavage of the otherwise recalcitrant aromatic C-O bonds with hydrogen gas under mild pressure (1 bar) and without reduction of arene rings. This group also discovered that the bio-derived solvent methyl formate can be used to convert sugars into furans with fuel-like properties. Methyl formate helps remove some of these OH groups that are plentiful in sugars and caps the others as methoxy groups, which are ideal components of automotive fuels.
Rauchfuss’s research team developed a method using formic acid to deoxygenate furanyl alcohols and furfurals relevant to the production of the potential fuel dimethylfuran (DMF). In related work, they developed methods for converting fructose to furans using bio-derived formic acid. Researchers developed selective, nickel-catalyzed hydrogenolysis of aromatic C-O bonds in alkyl aryl and diaryl ethers that form exclusively arenes and alcohols. The process allows for cleavage of all important aryl ether linkages with high yields at low pressure of hydrogen.
Researchers developed a new method for making the gasoline-like substance DMF from fructose. Key to their progress was the use of formic acid, which plays two roles. First, formic acid helps reorganize the carbon-oxygen bonds in fructose to give the intermediate called HMF. Subsequently, formic acid breaks some of the C-O bonds in HMF to give DMF. In breaking the C-O bonds, formic acid essentially serves as a form of liquid hydrogen. The group is screening for new reagents that break C-O bonds.
Published in 2010
Efficient Production of the Liquid Fuel 2,5-Dimethylfuran from Fructose Using Formic Acid as a Reagent, Todsapon Thananatthanachon and Thomas Rauchfuss, Angewandte Chemie International Edition, DOI: 10.1002/anie.201002267, August 2, 2010.
Published in 2009
Complexes of Lignols With Manganese and Ruthenium, Didier Morvan, Thomas Rauchfuss, Scott Wilson, Organometallics, 28(11): pp. 3161-3166, May 13, 2009.