Center for Enabling New Technologies Through Catalysis
A NSF Center for Chemical Innovation
Non-Enzymatic Disassembly of Lignocellulose
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.
Hanson, S. K.; Wu, R.; Silks, L. A. “Pete”, “C–C
or C–O Bond Cleavage in a Phenolic Lignin Model Compound: Selectivity Depends on
Angew. Chem. Int. Ed. 2012, in press.
Matson, T. D.; Barta, K.;
Iretskii, A. V.; Ford, P. C.
“One-Pot Catalytic Conversion of Cellulose
and of Woody Biomass Solids to Liquid
Am. Chem. Soc. 2011,
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
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,
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,
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,
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),
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,
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