MRI of Heterogeneous Hydrogenation Reactions Using Parahydrogen Polarization

PDF Version Also Available for Download.

Description

The power of magnetic resonance imaging (MRI) is its ability to image the internal structure of optically opaque samples and provide detailed maps of a variety of important parameters, such as density, diffusion, velocity and temperature. However, one of the fundamental limitations of this technique is its inherent low sensitivity. For example, the low signal to noise ratio (SNR) is particularly problematic for imaging gases in porous materials due to the low density of the gas and the large volume occluded by the porous material. This is unfortunate, as many industrially relevant chemical reactions take place at gas-surface interfaces in ... continued below

Physical Description

213

Creation Information

Burt, Scott R & Burt, Scott R. June 25, 2008.

Context

This thesis or dissertation is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this document can be viewed below.

Who

People and organizations associated with either the creation of this thesis or dissertation or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this thesis or dissertation. Follow the links below to find similar items on the Digital Library.

Description

The power of magnetic resonance imaging (MRI) is its ability to image the internal structure of optically opaque samples and provide detailed maps of a variety of important parameters, such as density, diffusion, velocity and temperature. However, one of the fundamental limitations of this technique is its inherent low sensitivity. For example, the low signal to noise ratio (SNR) is particularly problematic for imaging gases in porous materials due to the low density of the gas and the large volume occluded by the porous material. This is unfortunate, as many industrially relevant chemical reactions take place at gas-surface interfaces in porous media, such as packed catalyst beds. Because of this severe SNR problem, many techniques have been developed to directly increase the signal strength. These techniques work by manipulating the nuclear spin populations to produce polarized} (i.e., non-equilibrium) states with resulting signal strengths that are orders of magnitude larger than those available at thermal equilibrium. This dissertation is concerned with an extension of a polarization technique based on the properties of parahydrogen. Specifically, I report on the novel use of heterogeneous catalysis to produce parahydrogen induced polarization and applications of this new technique to gas phase MRI and the characterization of micro-reactors. First, I provide an overview of nuclear magnetic resonance (NMR) and how parahydrogen is used to improve the SNR of the NMR signal. I then present experimental results demonstrating that it is possible to use heterogeneous catalysis to produce parahydrogen-induced polarization. These results are extended to imaging void spaces using a parahydrogen polarized gas. In the second half of this dissertation, I demonstrate the use of parahydrogen-polarized gas-phase MRI for characterizing catalytic microreactors. Specifically, I show how the improved SNR allows one to map parameters important for characterizing the heat and mass transport in a heterogeneous catalyst bed. This is followed by appendices containing detailed information regarding the design and use of my experimental setup.

Physical Description

213

Source

  • Related Information: Designation of Academic Dissertation: Doctoral Thesis; Academic Degree: Ph.D.; Name of Academic Institution: University of California, Berkeley; Location of Academic Institution: Berkeley

Language

Identifier

Unique identifying numbers for this document in the Digital Library or other systems.

  • Report No.: LBNL-683E
  • Grant Number: DE-AC02-05CH11231
  • Office of Scientific & Technical Information Report Number: 934962
  • Archival Resource Key: ark:/67531/metadc901750

Collections

This document is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this thesis or dissertation?

When

Dates and time periods associated with this thesis or dissertation.

Creation Date

  • June 25, 2008

Added to The UNT Digital Library

  • Sept. 27, 2016, 1:39 a.m.

Description Last Updated

  • Oct. 2, 2017, 4:24 p.m.

Usage Statistics

When was this document last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 4

Interact With This Thesis Or Dissertation

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Burt, Scott R & Burt, Scott R. MRI of Heterogeneous Hydrogenation Reactions Using Parahydrogen Polarization, thesis or dissertation, June 25, 2008; Berkeley, California. (digital.library.unt.edu/ark:/67531/metadc901750/: accessed September 26, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.