Research output: Contribution to journal › Article › peer-review
FTIR study of unsupported molybdenum sulfide - In situ synthesis and surface properties characterization. / Tsyganenko, A. A.; Can, F.; Travert, A.; Maugé, F.
In: Applied Catalysis A: General, Vol. 268, No. 1-2, 10.08.2004, p. 189-197.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - FTIR study of unsupported molybdenum sulfide - In situ synthesis and surface properties characterization
AU - Tsyganenko, A. A.
AU - Can, F.
AU - Travert, A.
AU - Maugé, F.
PY - 2004/8/10
Y1 - 2004/8/10
N2 - Self-supporting molybdenum sulfide samples with high surface area were prepared by in situ thermal decomposition in vacuum of ammonium thiomolybdate. BET specific surface area of the resulting material has its highest values of about 120m2/g for samples treated in situ at 473K and decreases on further heating, while the composition of samples treated at 423-473K is close to MoS3, and after heating up to 573K corresponds to MoS2. FTIR spectra show that precursor decomposition is almost completed already after treatment at 423K, although the sample still contains admixed ammonium ions. After 473K most of contaminations are gone. Spectra of adsorbed NH 3, ND3, CO, SO2, CO2, COS and CH3SH adsorbed on samples pretreated at 423-473K are very close to those obtained for air-contacted MoS2 powder. However higher band intensities and the use of labeled compound enabled us to identify the bands of coordinately bonded NH3 molecules and to point to the existence of acidic sites capable to protonate ammonia. Molecularly adsorbed CH3SH could be distinguished from its dissociative form; this reveals the existence of acid-base pair sites on bulk molybdenum sulfide.
AB - Self-supporting molybdenum sulfide samples with high surface area were prepared by in situ thermal decomposition in vacuum of ammonium thiomolybdate. BET specific surface area of the resulting material has its highest values of about 120m2/g for samples treated in situ at 473K and decreases on further heating, while the composition of samples treated at 423-473K is close to MoS3, and after heating up to 573K corresponds to MoS2. FTIR spectra show that precursor decomposition is almost completed already after treatment at 423K, although the sample still contains admixed ammonium ions. After 473K most of contaminations are gone. Spectra of adsorbed NH 3, ND3, CO, SO2, CO2, COS and CH3SH adsorbed on samples pretreated at 423-473K are very close to those obtained for air-contacted MoS2 powder. However higher band intensities and the use of labeled compound enabled us to identify the bands of coordinately bonded NH3 molecules and to point to the existence of acidic sites capable to protonate ammonia. Molecularly adsorbed CH3SH could be distinguished from its dissociative form; this reveals the existence of acid-base pair sites on bulk molybdenum sulfide.
KW - Acidity
KW - Adsorption
KW - Ammonium tetrathiomolybdate
KW - Basicity
KW - Infrared spectroscopy
KW - MoS
KW - Surface sites
UR - http://www.scopus.com/inward/record.url?scp=2942582322&partnerID=8YFLogxK
U2 - 10.1016/j.apcata.2004.03.038
DO - 10.1016/j.apcata.2004.03.038
M3 - Article
AN - SCOPUS:2942582322
VL - 268
SP - 189
EP - 197
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
SN - 0926-860X
IS - 1-2
ER -
ID: 13733907