A significant fraction of the routes proposed for the production of liquid fuels from lignocellulose require heterogeneous catalysts to operate in water. While conventional heterogeneous catalysts developed for petroleum conversion chemistry are capable of catalyzing many of these conversions, the activity, selectivity and stability of these catalysts are not optimized and all three properties of the catalyst will be influenced to some extent by solvation effects. The lack of understanding of the role of solvation during biomass conversion chemistry impedes our ability to design optimized catalysts and processes for biofuel production. The role of water in biomass conversion catalysis not only has implications on materials selection, but can influence catalytic activity and selectivity through the stabilization or destabilization of adsorbed reactants and transition states by water solvation.
Professor Robert Rioux at the Pennsylvania State University, University Park, PA, proposes a research program to address this lack. His hypothesis is that heterogeneous catalysts with tailored hydrophobicity will demonstrate higher activity for biomass-derived feedstock conversion. He suggests that effective tailoring of the environment around an active site through the choice of ligand can reduce the influence of water inhibition, and that inherently the support of a heterogeneous catalyst can be considered a ligand and therefore modified to impart various levels of hydrophobicity. He will probe the extent to which hydrophobic modification of solid acid and cooperative acid-base heterogeneous catalysts can minimize solvation effects without negatively influencing catalysis.
The proposed research is an integration of homogeneous catalysis with heterogeneous catalysis into a catalyst design framework with solution thermodynamics to develop highly active and selective biomass-conversion catalysts for aqueous phase processing. Research projects within the scope of this proposal will be offered to undergraduate women and underrepresented groups through the university MURE and WISER programs. The work will be disseminated to the general public through an effort the PI is coordinating in conjunction with the Pennsylvania Institutes for Energy and the Environment to demonstrate the impact catalyst technology plays in the conversion of biomass to biofuels. Overall the Rioux proposal highlights the important role heterogeneous catalysis will play in the conversion of biomass into a sustainable, renewable energy source.
