TY - JOUR
T1 - Studies of sol-gel TiO 2 and Pt/TiO 2 catalysts for NO reduction by CO in an oxygen-rich condition
AU - Wang, J. A.
AU - Cuan, A.
AU - Salmones, J.
AU - Nava, N.
AU - Castillo, S.
AU - Morán-Pineda, M.
AU - Rojas, F.
N1 - Funding Information:
Dr. J. Navarrete Bolaños is gratefully acknowledged for fruitful discussion. The authors also thank the Mexican Institute of Petroleum and National Polytechnic Institute for financial support (Grant No. FIES-98-29-III and CGPI-IPN-20021187).
PY - 2004/5/31
Y1 - 2004/5/31
N2 - The textural properties, morphological features, surface basicity and oxygen reduction behaviours of titania and Pt supported titania catalysts synthesized via a sol-gel method were studied by means of N 2 physisorption, SEM, TEM, CO 2 -TPD and H 2 -TPR techniques. Mesostructured TiO 2 shows a very narrow pore size distribution that uniformly centred at about 4nm. High resolution TEM images confirmed that most of Pt particles on Pt/TiO 2 -SG had a size smaller than 2nm. Both the titania support and Pt loaded catalysts chiefly contained weak basic sites with small amount of strong basic sites. Loading Pt did not significantly alter the surface reduction characters of titania, indicating a weak interaction between Pt metals and titania support. Catalytic evaluation revealed that the selectivity of NO reduction over titania was insensitive to variation of textural property. On the bare titania, low NO conversion but high selectivity to N 2 O was obtained. However, the Pt/TiO 2 -SG catalysts exhibited high NO conversion and high selectivity to N 2 , which is assumed to relate to NO dissociation catalysed by the metallic Pt clusters. In addition, when the reaction temperature was above 200 °C, 3-11% NO 2 was yielded over the Pt/TiO 2 -SG catalysts, which was discussed on a basis of reaction competition, metal-support interaction and NO dissociation.
AB - The textural properties, morphological features, surface basicity and oxygen reduction behaviours of titania and Pt supported titania catalysts synthesized via a sol-gel method were studied by means of N 2 physisorption, SEM, TEM, CO 2 -TPD and H 2 -TPR techniques. Mesostructured TiO 2 shows a very narrow pore size distribution that uniformly centred at about 4nm. High resolution TEM images confirmed that most of Pt particles on Pt/TiO 2 -SG had a size smaller than 2nm. Both the titania support and Pt loaded catalysts chiefly contained weak basic sites with small amount of strong basic sites. Loading Pt did not significantly alter the surface reduction characters of titania, indicating a weak interaction between Pt metals and titania support. Catalytic evaluation revealed that the selectivity of NO reduction over titania was insensitive to variation of textural property. On the bare titania, low NO conversion but high selectivity to N 2 O was obtained. However, the Pt/TiO 2 -SG catalysts exhibited high NO conversion and high selectivity to N 2 , which is assumed to relate to NO dissociation catalysed by the metallic Pt clusters. In addition, when the reaction temperature was above 200 °C, 3-11% NO 2 was yielded over the Pt/TiO 2 -SG catalysts, which was discussed on a basis of reaction competition, metal-support interaction and NO dissociation.
KW - Catalysts
KW - NO reduction
KW - Pt/TiO
KW - Sol-gel synthesis
KW - Titania
UR - http://www.scopus.com/inward/record.url?scp=2542439069&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2004.02.057
DO - 10.1016/j.apsusc.2004.02.057
M3 - Artículo
SN - 0169-4332
VL - 230
SP - 94
EP - 105
JO - Applied Surface Science
JF - Applied Surface Science
IS - 1-4
ER -