Development of Group 9 Transition Metal Catalysts for Hydrocarbon Functionalization

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

With this award, the Chemical Catalysis Program of the Chemistry Division is funding Professor T. Brent Gunnoe of the University of Virginia to study the development of catalysts that can selectively convert hydrocarbons, compounds that only contain hydrogen and carbon atoms, into more complex compounds. Hydrocarbons from fossil resources form the foundation of the chemical industry and the energy sector. Recent years have seen an increase in access to vast amounts of domestic natural gas reserves; however, with current technological infrastructure the ability to transport natural gas economically is limited and therefore much natural gas in the U.S. and around the world remains "stranded" and unusable. Also, despite years of development, chemical processes that convert hydrocarbons into higher value chemicals often suffer from low selectivity for a desired compound and the requirement of high temperatures and pressures. Thus, new catalysts for alkane functionalization are essential for use of natural gas, and other hydrocarbons, as a precursor to new chemicals and transportation fuel. This research project is also providing training to undergraduate and graduate students to enable a future generation of scientists to work in the area of catalysis as it relates to the efficient use of fossil resources. The PI has also participated in several outreach and workshop events hosted by the University of Virginia's "More Than the Score" program, the Darden School of Business, and the "Car of the Future Summit." Professor Gunnoe is synthesizing and studying group 9 transition metal complexes for the catalytic functionalization of hydrocarbons. This project builds on preliminary work in the Gunnoe group that demonstrated the ability of novel rhodium complexes to activate the carbon-hydrogen bonds of hydrocarbons under acidic conditions. These results are being extended to a detailed study of all steps in the desired catalytic cycles, including the carbon-hydrogen activation step (both arenes and alkanes), oxidation of the transition metal hydrocarbyl complex, and reductive functionalization of the metal-hydrocarbyl ligand. Reactions in acidic media are being targeted that yield oxy-functionalized compounds such as esters. One objective seeks to understand how to rationally design catalysts based upon cobalt, rhodium and iridium to optimize the rate of carbon-hydrogen activation in acidic solvent. A second thrust seeks to develop and understand optimization of reductive functionalization in acidic solvent. The third objective combines these individual steps into catalytic processes for oxidative hydrocarbon functionalization.