Senior Investigators: Prof. Tom Baker (U. of Ottawa), Prof. Tom Cundari (U. of North Texas), Dr. Susan Hanson (LANL), Prof. Susannah Scott (UCSB), Dr. David Thorn (LANL).  

Global energy consumption is projected to double over the next three decades, placing severe demands both on the environment and on existing fossil fuel reserves. The development of alternatives to fossilized carbon as feedstocks for fuels and for chemical precursors for plastics, fabrics, and other valuable commodities is thus increasingly urgent. Non-food biomass represents one such alternative, since it is both renewable and, in principle, carbon-neutral. The Department of Energy has estimated that the amount of non-food biomass available annually is equivalent in energy to 3 billion barrels of liquid transportation fuel. This material is largely lignocellulose; thus, developing fundamental catalytic strategies to unlock this resource would have major economic, strategic and environmental ramifications.

The chemical approaches necessary to convert biomass to fuels and chemicals are fundamentally different than those needed for petroleum. In petrochemical catalysis, key tasks are to introduce functionality into unreactive hydrocarbons at elevated temperatures and pressures, and to assemble smaller molecules into larger ones (e.g., polymers). In contrast, lignocellulosic feedstocks require new catalysis strategies to disassemble these highly functionalized biopolymers and to prepare higher value compounds via selective removal and transformations of functional groups.

Cellulose is a linear polymer of D-glucose linked by β(1,4)-glycosidic bonds and the most plentiful biopolymer in the world. The closely associated lignins, which constitute up to 30% of woody biomass, are heterogeneous biopolymers with irregular structures. Most approaches to catalyzed lignocellulose deconstruction utilize C-O bond cleavage. CENTC has concentrated instead on oxidative cleavage of C-C bonds to transform lignin and cellulose into useful chemicals. For example, the vanadium complexes shown below have been shown to catalyze aerobic oxidation of lignin models.

Matson, T. D.; Barta, K.; Iretskii, A. V.; Ford, P. C.  “One-Pot Catalytic Conversion of Cellulose and of Woody Biomass Solids to Liquid Fuels”, J. Am. Chem. Soc. 2011, 133, 14090-14097.
(DOI: 10.1021/ja205436c)

Sedai, B.; Diaz-Urrutia, C.; Baker, R. T.; Wu, R.; Silks, L. A. “Pete”; Hanson, S. K. “Comparison of Copper and Vanadium Homogeneous Catalysts for Aerobic Oxidation of Lignin Models”, ACS Catalysis, 2011, 1, 794-804.
(DOI: 10.1021/cs200149v)

Hanson, S. K.; Baker, R. T.; Gordon, J. C.; Scott, B. L.; Silks, L. A. "Pete"; Thorn, D. L., "Mechanism of Alcohol Oxidation by Dipicolinate Vanadium(V): Unexpected Role of Pyridine", J. Am. Chem. Soc., 2010, 132, 17804-17816.
(DOI:10.1021/ja105739k)

Barta, K.; Matson, T. D.; Fettig, M. L.; Scott, S. L.; Iretskii, A. V.; Ford, P. C., "Catalytic disassembly of an organosolv lignin via hydrogen transfer from supercritical methanol", Green Chemistry , 2010, 12, 1640-1647.
(DOI: 10.1039/C0GC00181C)

Hanson, S. K.; Baker, R. T.; Gordon, J. C.; Scott, B. L.; Thorn, D. L., "Aerobic Oxidation of Lignin Models Using a Base Metal Vanadium Catalyst", Inorg. Chem., 2010, 49, 5611-5618.
(DOI: 10.1021/ic100528n)

Hanson, S. K.; Baker, R. T.; Gordon, J. C.; Scott, B. L.; Sutton, A. D.; Thorn, D. L. "Aerobic Oxidation of Pinacol by Vanadium(V) Dipicolinate Complexes: Evidence for Reduction to Vanadium(III)" J. Am. Chem. Soc. 2009, 131 (2), 428–429 (DOI: 10.1021/ja807522n)

Macala, Gerald S.; Robertson, Andrew W.; Johnson, Charles L.; Day, Zachary B.; Lewis, Robert S.; White, Mark G.; Iretskii, Alexei V.; Ford, Peter C. "Transesterification Catalysts from Iron Doped Hydrotalcite-like Precursors: Solid Bases for Biodiesel Production" Catalysis Letters, 2008, 122(3-4), 205-209 (DOI: 10.1007/s10562-008-9480-y)

Macala, G. S.; Matson, T. D.; Johnson, C. L.; Lewis, R.; Iretskii, A. V.; Ford, P. C. “Hydrogen Transfer from Super-critical Methanol over a Solid Base Catalysts. A Model for Lignin Depolymerization” ChemSusChem, 2009, 2, 215-217.
(DOI: 10.1002/cssc.200900033)