TEMPERATURE-SWITCHED MAS NMR - A NEW METHOD FOR TIME-RESOLVED IN-SITUSTUDIES OF REACTION STEPS IN HETEROGENEOUS CATALYSIS

Citation
H. Ernst et al., TEMPERATURE-SWITCHED MAS NMR - A NEW METHOD FOR TIME-RESOLVED IN-SITUSTUDIES OF REACTION STEPS IN HETEROGENEOUS CATALYSIS, Chemical physics letters, 229(3), 1994, pp. 291-296
Citations number
12
Categorie Soggetti
Physics, Atomic, Molecular & Chemical
Journal title
ISSN journal
00092614
Volume
229
Issue
3
Year of publication
1994
Pages
291 - 296
Database
ISI
SICI code
0009-2614(1994)229:3<291:TMN-AN>2.0.ZU;2-Y
Abstract
The temperature of zeolite samples containing adsorbed methanol molecu les was switched from room temperature to 500-600 K within 30-40 s by means of a laser beam. The catalytic reaction was monitored by C-13 MA S NMR and H-1 MAS NMR, the latter in steps of one second. A two-dimens ional Fourier-transformation of the difference between the time-depend ent and the equilibrium state of the system gives a good representatio n of reaction steps. For the methanol conversion it was found that the primarily formed C-3/C-4 alkanes are still involved in further reacti ons, whereas methane is an inert product under these conditions.