BERKELEY, CA -- In a significant step towards improving the design of future catalysts and catalytic reactors, especially for microfluidic lab-on-a-chip devices, researchers with the U.S. Department of Energys Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) at Berkeley, have successfully applied magnetic resonance imaging (MRI) to the study of gas-phase reactions on the microscale.
Under the leadership of Alexander Pines, faculty senior scientist in Berkeley Labs Materials Sciences Division and the Glenn T. Seaborg Professor of Chemistry at UC Berkeley, a team of researchers that included chemists Louis Bouchard and Scott Burt have developed a technique in which parahydrogen-polarized gas is used to make an MRI signal strong enough to provide direct visualization of the gas-phase flow of active catalysts in packed-bed microreactors. This work, the first application of gas-phase MRI to microfluidic catalysis, shows that parahydrogen-enhanced MRI can be used to track gases and liquids in microfluidic devices as well as in the void spaces of a tightly packed catalyst reactor bed.
This is the first time hyperpolarized gas has been used to directly study catalytic reaction products on such a small scale and without the use of tracer particles or gas, says Bouchard. It opens the door for future studies of heterogeneous catalysis in which all the unique benefits of MRI, such as velocimetry and spatially dependent quantities, are available.
Adds Burt, Furthermore, our results indicate that our approach to using parahydrogen can be extended to other chemical reactions beyond hydrogenation, which significantly broadens the impact and potential use of our technique.
Pines, Bouchard and Burt are the co-authors of a paper published in the January 25, 2008 edition of the journal Science, describing this research. The paper is entitled: NMR Imaging of Catalytic Hydrogenation in Microreactors wit
|Contact: Lynn Yarris|
DOE/Lawrence Berkeley National Laboratory