Stowers Laboratory Research
Stowers Laboratory Research
The Stowers laboratory takes an interdisciplinary approach towards research of carbon dioxide activation and reactivity through principles of inorganic, physical and organic chemistry. Our interest is in developing new catalysts that will decrease the energy and waste required to synthesize commodity chemicals through new pathways. Some commodity chemicals of interest are using CO2 to form esters or alcohols, as well as using bio-based feedstocks, such as glycerol, as alternative starting points to get to these products. Determining the principles necessary for the activation of CO2 towards C-C bond formation will be achieved using a variety of tools and techniques.
Using Carbon Dioxide as a Feedstock
Carbon dioxide is an undesired byproduct of combustion. Finding ways to manage and use carbon dioxide is an important strategy for keeping emissions low without affecting the economy. Although it is often seen as kinetically unreactive, recently a number of catalysts have been shown to overcome this barrier for the production of higher-value chemicals. Glycerol is another waste stream that has a high density of functionality that can be converted to platform chemicals such as propanediols, allyl alcohol and propylene. Catalyst selectivity and efficiency are paramount for maximizing the conversion of glycerol.
Inorganic synthesis of Heterogeneous Catalysts
Heterogeneous catalysts can provide good separation from the starting materials thus decreasing waste although this can erode selectivity. Synthesizing and characterizing new nanoparticle and supported catalysts allow us to determine how CO2 interacts with the surface and ultimately reacts towards C-C bond formation. Aims include synthesizing inorganic catalysts, determining the catalyst structure by X-ray crystallography, SEM and XPS, and testing the catalysts for catalytic activity in organic reactions. We are also interested in inorganic deoxygenation catalysts and mechanisms, with particular interest in Molybdenum.
Gas-phase Reactivity of Carbon Dioxide
Using synthesized and commercially available catalysts, a plug flow gas-phase reactor is used to capture CO2 on CNT synthesized materials. Using these materials as a starting point, catalyst bifunctionality will be introduced to determine how to react the CO2. Determination of products are analyzed with online gas chromatography/mass spectrometry techniques and analysis. Aims include using a gas-flow reactor and high pressure/high temperature reactor, design of experiments to determine conversion and reactivity, analyze outcomes, help determine target reactions, and characterize products via GCMS or NMR.
Mechanistic Studies on Catalyst Surfaces
Heterogeneous catalysts are becoming easier to study with new spectroscopy techniques that allow characterization of the mechanism at the surface of the material. The goals of this project will be to study catalysts in ultra-high vacuum in order to understand active sites, activation, deactivation and poisoning, intermediates of reaction mechanisms in the aim to optimize and develop catalysts and reactions for C-C bond formation using CO2. Aims include analyzing reactions on catalysts surfaces via in-situ XPS and temperature-programmed reaction spectroscopy in ultra-high vacuum and developing new reactions.