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Investigation of Catalyst Reaction Mechanisms by In-situ High Field, High Resolution NMR Spectroscopy


EMSL Project ID
10601

Abstract

We propose to develop novel NMR methods suitable for studies of both catalyst materials and adsorption intermediates for heterogeneous catalysis compromising dispersed metal oxide domains and molecular clusters containing tungsten, vanadium metals as active components. A new approach that combines the features of both magic angle turning (MAT) and magic angle hopping (MAH) technologies will be investigated. Precise control over reaction conditions such as temperature, pressure, flow conditions, and feed compositions is possible with this method. Under these conditions the reaction mechanisms can be studied in-situ as well as the possibility to study chemical and physical properties of the catalyst in-situ. High-level electronic structure calculations at the density function theory and molecular orbital theory levels will be used to interpret key NMR parameters such as chemical shift tensors and quadrupolar coupling constant, including the electronic field gradient tensors. In the current application, the new in situ method will be used to study two model catalytic processes, i.e., the redox (oxidative conversion of methanol to formaldehyde) and the acid chemistry (alcohol dehydration and isobutene reactions). However, the in-situ characterization of a catalytic reaction process by the proposed methodologies can be applied to a large variety of catalytic processes.

Project Details

Start Date
2004-11-15
End Date
2005-10-03
Status
Closed

Team

Principal Investigator

Jian-zhi Hu
Institution
Pacific Northwest National Laboratory

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