This project aims to develop an efficient system for selective oxidation of a wide range of organic substrates including compounds containing unactivated C-H bonds. We recently reported the synthesis and characterization of a highly active heterogeneous cobalt water oxidation catalyst formed from simple and abundant starting materials. We are investigating its use in conjunction with an environmentally benign oxidant to selectively oxidize organic substrates under mild reaction conditions.
Development of heterogeneous first row transition metal catalysts could enable larger scale implementation of selective C-H oxidation for more efficient drug synthesis, fine chemical synthesis, and conversion of feedstock chemicals.
Samuel L. Collom, Aaron J. Bloomfield, and Paul T. Anastas; A Heterogeneous Cobalt Catalyst for Selective C-H Oxidation with KHSO5 as the Terminal Oxidant; Green Chemistry Letters and Reviews (in Progress)
Aaron J. Bloomfield, Stafford W. Sheehan, Samuel L. Collom, and Paul T. Anastas; Performance Enhancement for Electrolytic Systems through the Application of a Cobalt-based Heterogeneous Water Oxidation Catalyst; ACS Sustainable Chem. Eng. 2015, 3, 1234−1240.
Aaron J. Bloomfield, Stafford W. Sheehan, Samuel L. Collom, Robert H. Crabtree and Paul T. Anastas; A heterogeneous water oxidation catalyst from dicobalt octacarbonyl and 1,2-bis(diphenylphosphino)ethane; New Journal of Chemistry, 2014, 38, 1540-1545.
Aaron J. Bloomfield, Stafford W. Sheehan, Samuel L. Collom, Robert H. Crabtree and Paul T. Anastas; Metal oxide-?organic hybrid materials for heterogeneous catalysis and methods of making and using thereof; US Patent 20150065339
Extensive water and air quality monitoring of fossil fuel extraction allows us to track the environmental impacts of these operations. However, the long-term impacts remain unclear. Furthermore, the samples are often highly complex and contain chemicals that are not typically looked for in routine analyses. Our focus is to improve routine analytical techniques for high-throughput analyses of environmental samples associated with unconventional fossil fuel development.
In hydraulic fracturing, our research has focused on hydrophobic organic compounds in groundwater near natural gas wells in Pennsylvania. We employed state of the art analytical technologies to detect trace levels of compounds related to the hydraulic fracturing process. Our work on Canadian tar sands has focused on the organic chemicals emitted to the atmosphere during the refinement process at various temperatures. A common link between the two aspects of our research was the complex nature of the samples we collected. Going forward, our focus will be to improve the way we collect and process our samples to reduce the time, energy, and cost of routine environmental analyses.
Co-location of industrial operations and residential communities is necessary for domestic fuel production. Our ultimate goal is to promote safe practices that will reduce the impact on human and environmental health by providing the necessary means to collect and analyze high-quality data.
With the rising energy crisis, fossil fuel dependence is not sustainable. In the long run, developing alternative sources of energy is necessary. Energy security for the United States and other oil importing nations is an escalating issue which has diverted much focus and research towards biofuels. Biofuels, a renewable source of energy, are readily produced from a variety of biomass materials.
Biodiesel, a fatty acid methyl esters, has seen increased use and can be harnessed from plant oils and animal fats. Production of biodiesel requires the extraction of the oils, essentially triglycerides, which can then be transformed into biodiesel via transesterification. We are using supercritical carbon dioxide, a benign solvent, to perform extraction prior to a heterogeneous catalyzed transesterification. The differential solubility of biomass constituents in supercritical carbon dioxide allows for fractionation in which only the targeted compounds are extracted. As a result, other value-added products can be isolated which will enhance bio-refinery and boost the value of this process.
We are currently evaluating the effect of substrate composition on reaction kinetics during the transesterification process by varying the degree of unsaturation and the carbon chain length. Overall, this study will help us gain a deeper understanding of the system conditions critical to the biomass conversion process. Using our data to create a model will be very useful, as it will help us tailor the conditions necessary for a particular biomass source due to composition variations.