Photocatalytic epoxidation of propene: Fundamental studies of uptake, binding, and reaction mechanisms
Abstract
A fundamental understanding of the mechanisms that drive the direct photocatalytic oxidation of propene to form propene oxide will be developed through a systematic study of oxygen, propene , and propene oxide chemistry at a prototypical TiO2-SiO2 binary catalyst. This work is motivated by the importance of developing a fundamental understanding of photocatalysis within binary systems and by the potential to develop new, more efficient and selective routes to the production of propene oxide, which is a critically important commodity compound. The experiments are facilitated by employing in situ infrared spectroscopic detection of surface-bound species while simultaneously tracking, via mass spectrometry, the evolution of gas-phase products during exposure of the catalyst to a precision-controlled flux of propene, oxygen, and photons. Three primary research objectives will guide this investigation: {l) Oxygen uptake mechanism: Characterize fundamental aspects of O2 adsorption at TiO2-SiO2 binary catalysts in the dark and during UV irradiation through isotopic labeling, infrared spectroscopy, and temperature-programmed desorption measurements. (2) Propene uptake and binding energetics: Determine the initial uptake mechanism and energetics of propene on TiO2-SiO2 binary catalysts, as well as the influence of photons, titanium loading, and sample history on binding. (3) Charge transfer and oxidation: Uncover the dynamics of propene + 02 + hv chemistry through studies of propene and oxygen binding when co-adsorbed to the catalyst and exposed to radiation. The ultimate long-term merit of the proposed research will be to develop strategies for creating new catalysts that maximize the efficiency of propene oxide production , while removing many of the environmental hazards associated with current technologies.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 11, 2018
- Source ID
- W911NF1710327
Entities
People
- John A Morris
Organizations
- Army Contracting Command
- United States Army
- Virginia Tech