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Title: A new combined nuclear magnetic resonance and Raman spectroscopic probe applied to in situ investigations of catalysts and catalytic processes

Both Raman and nuclear magnetic resonance (NMR) spectroscopies are valuable analytical techniques capable of providing mechanistic information and thereby providing insights into chemical processes, including catalytic reactions. Since both techniques are chemically sensitive, they yield not only structural information but also quantitative analysis. In this work, for the first time, the combination of the two techniques in a single experimental apparatus is reported. This entailed the design of a new experimental probe capable of recording simultaneous measurements on the same sample and/or system of interest. The individual datasets acquired by each spectroscopic method are compared to their unmodified, stand-alone equivalents on a single sample as a means to benchmark this novel piece of equipment. The application towards monitoring reaction progress is demonstrated through the evolution of the homogeneous catalysed metathesis of 1‑hexene, with both experimental techniques able to detect reactant consumption and product evolution. This is extended by inclusion of magic angle spinning (MAS) NMR capabilities with a custom made MAS 7 mm rotor capable of spinning speeds up to 1600 Hz, quantified by analysis of the spinning sidebands of a sample of KBr. The value of this is demonstrated through an application involving heterogeneous catalysis, namely the metathesis ofmore » 2-pentene and ethene. This provides the added benefit of being able to monitor both the reaction progress (by NMR spectroscopy) and also the structure of the catalyst (by Raman spectroscopy) on the very same sample, facilitating the development of structure-performance relationships.« less
Authors:
;  [1] ;  [2] ;  [3]
  1. Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom)
  2. Johnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading RG4 9NH (United Kingdom)
  3. Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)
Publication Date:
OSTI Identifier:
22308799
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; BENCHMARKS; CATALYSTS; ETHYLENE; HETEROGENEOUS CATALYSIS; NUCLEAR MAGNETIC RESONANCE; POTASSIUM BROMIDES; PROBES; RAMAN SPECTROSCOPY