Para-Hydrogen-Enhanced Gas-Phase Magnetic Resonance Imaging
Herein, we demonstrate magnetic resonance imaging (MRI) inthe gas phase using para-hydrogen (p-H2)-induced polarization. A reactantmixture of H2 enriched in the paraspin state and propylene gas is flowedthrough a reactor cell containing a heterogenized catalyst, Wilkinson'scatalyst immobilized on modified silica gel. The hydrogenation product,propane gas, is transferred to the NMR magnet and is spin-polarized as aresult of the ALTADENA (adiabatic longitudinal transport and dissociationengenders net alignment) effect. A polarization enhancement factor of 300relative to thermally polarized gas was observed in 1D1H NMR spectra.Enhancement was also evident in the magnetic resonance images. This isthe first demonstration of imaging a hyperpolarized gaseous productformed in a hydrogenation reaction catalyzed by a supported catalyst.This result may lead to several important applications, includingflow-through porous materials, gas-phase reaction kinetics and adsorptionstudies, and MRI in low fields, all using catalyst-free polarizedfluids.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director. Office of Science. Office of Basic EnergySciences; US Department of Homeland Securities ContractDE-AC05-06OR23100; Russian Science Support foundation
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 923362
- Report Number(s):
- LBNL-63262; R&D Project: 508601; BnR: KC0203010; TRN: US200804%%1087
- Journal Information:
- Angewandte Chemie International Edition, Vol. 46, Issue 22; Related Information: Journal Publication Date: 23 Apr 2007
- Country of Publication:
- United States
- Language:
- English
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