RU-CU ZSM5 CATALYSTS - CHARACTERIZATION BY FT-IR SPECTROSCOPY/

Citation
C. Crisafulli et al., RU-CU ZSM5 CATALYSTS - CHARACTERIZATION BY FT-IR SPECTROSCOPY/, Applied surface science, 99(4), 1996, pp. 401-409
Citations number
34
Categorie Soggetti
Physics, Condensed Matter","Chemistry Physical","Materials Science, Coatings & Films
Journal title
ISSN journal
01694332
Volume
99
Issue
4
Year of publication
1996
Pages
401 - 409
Database
ISI
SICI code
0169-4332(1996)99:4<401:RZC-CB>2.0.ZU;2-D
Abstract
H-ZSMS supported Ru-Cu bimetallic catalysts have been studied by FT-IR spectroscopy. Experiments have been carried out on samples prepared f rom Ru(NO)(NO3)(3) and RuCl3. On the monometallic Ru/ZSMS samples adso rption of CO led to a band at 2046 cm(-1), due to CO linearly adsorbed on Ru-0, and several bands at higher frequencies related to CO on RU( delta+) species. A higher amount of Ru-delta+ species is formed on the ex-Ru(NO)(NO3)(3) sample, due to the smaller metal particle size of t his sample compared to the ex-RuCl3 one. On monometallic Cu/ZSMS two b ands at 2151 and 2158 cm(-1) are observed, both related to CO adsorbed on Cu+1 sites, formed through a reaction with the OH groups of the ze olite. On the bimetallic Ru-Cu samples, besides all the characteristic bands of the Ru and Cu monometallic samples, a band at 2138 cm(-1) at tributed to CO adsorbed on Cu bound to Ru has been detected, denoting the formation of Ru-Cu bimetallic particles. The FT-IR spectra indicat e that on the samples prepared from RuCl3 the extent of bimetallic Ru- Cu particles is higher than on those prepared from Ru(NO)(NO3)(3). Thi s behaviour, attributed to the presence of chlorine on the ex-RuCl3 sa mples, is in agreement with the catalytic performance of these systems in the hydrogenolysis of propane.