Change search
ReferencesLink to record
Permanent link

Direct link
NMR study of the chemisorption and decomposition of methylamine on Rh/SiO2
KTH, School of Information and Communication Technology (ICT), Material Physics.
2007 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 111, no 21, 7783-7794 p.Article in journal (Refereed) Published
Abstract [en]

Nuclear magnetic resonance (NMR) studies of the interaction of methylamine with the rhodium surface in a Rh/SiO2 catalyst at temperatures in the range of 253-298 K reveal two principal features in both the C-13 and N-15 spectra. One feature is a resonance occurring at a frequency very close to the resonance frequency for methylamine gas. This feature is attributed to methylamine molecules adsorbed without dissociation. Because the methylamine is not removed from the catalyst surface by evacuation to 10(-6) Torr, its interaction with the surface is reasonably strong. The silica support does not retain methylamine after such an evacuation, and therefore, the adsorbed methylamine is associated with the rhodium. The other feature in both the C-13 and N-15 spectra is a very broad resonance occurring downfield of the resonance for the nondissociatively adsorbed methylamine. It is attributed to partially dehydrogenated surface species designated by the generalized formula (CN)H-x. Incipient scission of carbon-nitrogen bonds is observed at room temperature. As the temperature is increased above room temperature, the extent of scission of the carbon-nitrogen bonds increases. Ammonia, methane, and higher-carbon-number hydrocarbons then appear in the gas phase. The nondissociatively adsorbed methylamine is continuously transformed into the species (CN)H-x, thereby releasing hydrogen on the surface. The hydrogen is consumed in the production of the ammonia and methane observed in the gas phase. Ammonia is formed much more readily than methane or the other hydrocarbons, with the result that the species remaining on the surface are rich in carbon relative to nitrogen.

Place, publisher, year, edition, pages
2007. Vol. 111, no 21, 7783-7794 p.
National Category
Physical Chemistry
URN: urn:nbn:se:kth:diva-37303DOI: 10.1021/jp0659251ISI: 000246695400033ScopusID: 2-s2.0-34250307185OAI: diva2:432991
Available from: 2011-08-08 Created: 2011-08-08 Last updated: 2012-03-22Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
von Schenck, Henrik
By organisation
Material Physics
In the same journal
The Journal of Physical Chemistry C
Physical Chemistry

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 24 hits
ReferencesLink to record
Permanent link

Direct link