Yale University
225 Prospect Street
New Haven, CT 06520
phone: 203.432.5215
greenchemistry@yale.edu

Energy

  • Selective C-H Oxidation Using a Heterogeneous Cobalt Catalyst and Green Oxidant

     Details...
    Activation of C-H bonds is of interest for converting feedstock chemicals from oil, natural gas, and biomass into higher value chemicals. Many of the catalysts that are currently employed in C-H activation require precious metals and so a current challenge is to replace these catalysts using earth-abundant and cheaper first row transition metals.

    STUDY

    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.


    IMPACT

    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. 

    PUBLICATIONS

    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

  • Analytical techniques to evaluate the environmental impacts of unconventional fossil fuel extraction

     Details...
    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.

    STUDY

    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.

    IMPACT

    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.

  • Extraction of Algal Lipids for Use in Biodiesel Production

     Details...
    The objective of this research is to contribute to the development of algal lipids as a viable biofuel energy source by optimizing lipid extraction techniques for efficiency, sustainability, decreased hazard, and selectivity.

    Due to the growing demand for energy and the depletion of non-renewable sources, alternative fuel sources need to be researched and brought to the level where viable implementation can occur.  To advance the realization of algae as a feedstock for biodiesel, process technologies and closed-loop biomass use must be optimized. The objective of this research is to develop the potential of algal lipid for use in biodiesel production by optimizing lipid extraction techniques for efficiency, sustainability, decreased hazard, and selectivity. In particular, extraction improvements will include cell disruption, greener solvent systems (i.e. supercritical fluid extraction), selective extraction, and simplified extraction-fuel conversion processes.  Further research will be conducted on algae cell optimization as a starting material as well as on potential end-use applications for unused biomass.

  • Oxidative Degradation of Lignin

     Details...
    Oxidative degradation of lignin model compounds using green oxidants, naturally abundant transition metals, and environmentally benign solvents.

    Our approach is to test different manganese based complexes and salts with green oxidants on lignin model compounds that we have prepared. These models allow us to more easily determine the extent and mode of oxidation that each set of complexes/oxidants are capable of. It is our intention to use naturally abundant transition metals, environmentally friendly oxidants, and the greenest solvents possible. Once we have a system that has been shown to degrade the models we can move on to actual lignin.