Sustainable Chemistry and Biomass Conversion

with a focus on lignin

The structure of lignin.

Biomass has increasingly become an attractive material for energy generation and the production of liquid fuels.  In addition to the carbohydrates cellulose and hemicellulose, biomass is comprised of about 25% lignin, a complex polymer consisting mostly of phenolic units.   Catalytically breaking down these materials with the ability to direct reaction selectivity toward aromatic products and other higher valuable products is essential.  We have thus far focused processes such as catalytichydrogenation and hydrogenolysis of the lignin in super-critical methanol applying earth abundant porous metal oxides (MgO/Al2O3 doped with Ni, Cu, and/or Nb as catalysts).  In addition, understanding the fundamental mechanistic chemistry allows for objective designs of new catalytic processes to enhance specificity and activity for environmentally safer and energy efficient chemical transformations. At present, this research is supported by the NSF-sponsored collaborative Center for Sustainable Use of Renewable Feedstocks (CenSURF).

The copper doped porous metal oxides used in our laboratory can convert lignin and lignocellulose composites to organic liquids without generating the intractable tars that are often the byproducts of such catalysis. The selectivity is currently poor, but ongoing studies of the fundamental disassembly and reduction pathways with model compounds and with the biopolymers themselves are providing the guidelines for developing product streams with much greater selectivity toward value-added products.