| AVS 55th International Symposium & Exhibition | |
| In Situ Microscopy and Spectroscopy: Interfacial and Nanoscale Science Topical Conference | Wednesday Sessions |
| Session IS+NS+TR-WeA |
| Session: | In Situ Microscopy and Spectroscopy – Interfacial Science and Catalysis |
| Presenter: | J.J. Ford, Pacific Northwest National Laboratory |
| Authors: | J.J. Ford, Pacific Northwest National Laboratory J.Z. Hu, Pacific Northwest National Laboratory J.A. Sears, Pacific Northwest National Laboratory J.H. Kwak, Pacific Northwest National Laboratory D.W. Hoyt, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
We have recently finished construction of a new NMR probe to study catalytic systems under conditions where the reactions actually occur. The probe uses a 9.5 mm commercially available MAS rotor system and is built to operate in a 500 MHz wide bore magnet. An integrated heater assembly is able to raise the sample temperature to 400C while the sample is spinning up to 3.5kHz. The rotor and stator assembly have been modified to allow a continuous flow of reactants through the rotor while it is spinning and at temperature. The carrier gas of either N2 or He can carry reactants into the probe and move products out of the probe. Inserts for the rotor diffuse the gas stream over the catalyst bed and collect it on the other side. This allows steady state NMR measurements to be made under conditions comparable to those in typical catalytic environment – high temperatures and a steady influx of reactants and exhaust of products. The high sensitivity from this larger sample volume probe allows 13C observation at natural abundance. Performance test results will be presented, including an investigation of the reaction mechanisms of the carbonylation of dimethyl ether to methyl acetate on mordenite. This work has been supported by an intramural capability grant from EMSL and a DOE-Catalyst grant.