TY - JOUR
T1 - Low temperature CO oxidation over Pd catalysts supported on highly ordered mesoporous metal oxides
AU - Jin, Mingshi
AU - Park, Jung Nam
AU - Shon, Jeong Kuk
AU - Kim, Jin Hoe
AU - Li, Zhenghua
AU - Park, Young Kwon
AU - Kim, Ji Man
PY - 2012/5/20
Y1 - 2012/5/20
N2 - Highly ordered mesoporous metal oxides (meso-MO x) such as CeO 2, Co 3O 4, Mn 2O 3, SnO 2, and TiO 2 were successfully synthesized by using nano-replication method, and Pd-loaded meso-MO x (Pd/meso-MO x) catalysts for CO oxidation were investigated. The catalysts were characterized by X-ray diffraction, N 2 adsorption-desorption, electron microscopy, CO-temperature programmed desorption (CO-TPD), and H 2-temperature programmed reduction (H 2-TPR). All of the catalysts exhibited highly ordered mesostructure and a high surface area (>100 m 2 g -1). The Pd-loading on meso-MO x supports enhanced catalytic activities compared with those of MO x supports only. Among the catalysts, Pd/meso-Co 3O 4 showed a high catalytic activity. The activities of Pd/meso-Co 3O 4 and Pd/meso-Mn 2O 3 were only slightly increased compared to the corresponding meso-MO x materials, whereas Pd/meso-CeO 2, Pd/meso-SnO 2 and Pd/meso-TiO 2 exhibited significant increases in the catalytic activities. XPS spectra showed that Pd species had strong interactions with meso-CeO 2, meso-SnO 2 and meso-TiO 2, and less interaction with meso-Co 3O 4 and meso-Mn 2O 3. These results suggest a synergistic effect between metal and the supports and the catalytic behaviours and activities are highly dependent on the nature of supports. The catalytic activities of Pd/meso-MO x can be further improved by a pre-reduction treatment. After H 2 pretreatment, all of the catalytic activities were increased. Especially, the Pd/meso-CeO 2 exhibited highest activity after the H 2 pretreatment. Because the pretreatment enhances metal-support interaction and the formation of oxygen vacancies and hydroxyl groups around Pd or the surface interaction phase, which is participated by influencing electronic state of the surface active sites.
AB - Highly ordered mesoporous metal oxides (meso-MO x) such as CeO 2, Co 3O 4, Mn 2O 3, SnO 2, and TiO 2 were successfully synthesized by using nano-replication method, and Pd-loaded meso-MO x (Pd/meso-MO x) catalysts for CO oxidation were investigated. The catalysts were characterized by X-ray diffraction, N 2 adsorption-desorption, electron microscopy, CO-temperature programmed desorption (CO-TPD), and H 2-temperature programmed reduction (H 2-TPR). All of the catalysts exhibited highly ordered mesostructure and a high surface area (>100 m 2 g -1). The Pd-loading on meso-MO x supports enhanced catalytic activities compared with those of MO x supports only. Among the catalysts, Pd/meso-Co 3O 4 showed a high catalytic activity. The activities of Pd/meso-Co 3O 4 and Pd/meso-Mn 2O 3 were only slightly increased compared to the corresponding meso-MO x materials, whereas Pd/meso-CeO 2, Pd/meso-SnO 2 and Pd/meso-TiO 2 exhibited significant increases in the catalytic activities. XPS spectra showed that Pd species had strong interactions with meso-CeO 2, meso-SnO 2 and meso-TiO 2, and less interaction with meso-Co 3O 4 and meso-Mn 2O 3. These results suggest a synergistic effect between metal and the supports and the catalytic behaviours and activities are highly dependent on the nature of supports. The catalytic activities of Pd/meso-MO x can be further improved by a pre-reduction treatment. After H 2 pretreatment, all of the catalytic activities were increased. Especially, the Pd/meso-CeO 2 exhibited highest activity after the H 2 pretreatment. Because the pretreatment enhances metal-support interaction and the formation of oxygen vacancies and hydroxyl groups around Pd or the surface interaction phase, which is participated by influencing electronic state of the surface active sites.
KW - CO oxidation
KW - Mesoporous metal oxides
KW - Metal-support interaction
KW - Pd
UR - http://www.scopus.com/inward/record.url?scp=84860221067&partnerID=8YFLogxK
U2 - 10.1016/j.cattod.2011.09.019
DO - 10.1016/j.cattod.2011.09.019
M3 - Article
AN - SCOPUS:84860221067
SN - 0920-5861
VL - 185
SP - 183
EP - 190
JO - Catalysis Today
JF - Catalysis Today
IS - 1
ER -