High temperature/pressure MAS-NMR for the study of dynamic processes in mixed phase systems
A new MAS-NMR rotor (the WHiMS rotor) has been developed which can reach pressures of 400 bar at 20 °C or 225 bar at 250 °C. These rotors are ideal for mixed phase systems such as a reaction using a solid catalyst with a liquid/supercritical solvent topped with high pressure gas in the head space. After solid and liquid portions of the sample are loaded, the rotor is capped with an o-ring equipped polymer bushing that snaps into a mating groove in the rotor. The bushings incorporate a check valve into the sealing mechanism which allows for pressurization without mechanical manipulation – they will allow gas to flow in but not out. This WHiMS rotor design has enabled experiments on a wide variety of biotic and abiotic mixed-phase systems. Geochemical systems have also been studied, for example, adsorption and confinement studies of supercritical methane/CO2 in clays and other minerals which display pressure dependent 13C chemical shifts. Example data from other mixed-phase chemical and microbial systems are reported. These include monitoring metabolite conversion of extremophilic bacteria found in subsurface systems at elevated pressures and real-time operando reactions in catalysis systems - with liquid-quality resolution for 1H and 13C NMR spectra.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- CBET-1512228; CBET-1604095; AC05-76RL01830
- OSTI ID:
- 1479148
- Alternate ID(s):
- OSTI ID: 1482210; OSTI ID: 1512259
- Report Number(s):
- PNNL-SA-138048; S0730725X18304259; PII: S0730725X18304259
- Journal Information:
- Magnetic Resonance Imaging, Journal Name: Magnetic Resonance Imaging Vol. 56 Journal Issue: C; ISSN 0730-725X
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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