TY - JOUR
T1 - Effect of Ag doping on Pd/Ag-CeO2 catalysts for CO and C3H6 oxidation
AU - Seo, Yaeun
AU - Lee, Min Woo
AU - Kim, Hyun Jae
AU - Choung, Jin Woo
AU - Jung, Chang Ho
AU - Kim, Chang Hwan
AU - Lee, Kwan Young
N1 - Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government ( MSIP ; NRF-2016R1A5A1009592 ).
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/8/5
Y1 - 2021/8/5
N2 - To achieve high fuel efficiency and low emission in automobiles, it is necessary to develop highly active diesel oxidation catalysts (DOCs). Pd/CeO2 catalysts have been widely used as active catalysts for CO and C3H6 oxidation reactions. Additionally, Ag has been reported to enhance the oxygen storage capacity (OSC) of CeO2, which contributes to the oxidation ability of Pd/CeO2. In this study, Pd/Ag-CeO2 catalysts were used for CO and C3H6 oxidation reactions. When CeO2 was doped with appropriate amounts of Ag, reducibility and CO desorption rate were increased, which confirmed the high OSCs of Ag-doped catalysts. However, Ag particles were formed and the Ce3+/Ce4+ ratio decreased when CeO2 was doped with excess amounts of Ag. In addition, reduced Pd (Pd0), which is an active species for C3H6 oxidation, was formed and maintained even under oxidative reaction conditions. Since the removal of C3H6 is important for the oxidation of CO and C3H6, the catalyst with the highest Pd0 fraction (Pd/0.1Ag-CeO2 and Pd/0.3Ag-CeO2) presented improved catalytic activity. Consequently, the optimal amount of Ag enhanced the OSC of Pd/Ag-CeO2 catalysts and formed active Pd0 species under oxidative conditions, which resulted in the excellent catalytic activity of Pd/Ag-CeO2 for the CO and C3H6 oxidation reaction.
AB - To achieve high fuel efficiency and low emission in automobiles, it is necessary to develop highly active diesel oxidation catalysts (DOCs). Pd/CeO2 catalysts have been widely used as active catalysts for CO and C3H6 oxidation reactions. Additionally, Ag has been reported to enhance the oxygen storage capacity (OSC) of CeO2, which contributes to the oxidation ability of Pd/CeO2. In this study, Pd/Ag-CeO2 catalysts were used for CO and C3H6 oxidation reactions. When CeO2 was doped with appropriate amounts of Ag, reducibility and CO desorption rate were increased, which confirmed the high OSCs of Ag-doped catalysts. However, Ag particles were formed and the Ce3+/Ce4+ ratio decreased when CeO2 was doped with excess amounts of Ag. In addition, reduced Pd (Pd0), which is an active species for C3H6 oxidation, was formed and maintained even under oxidative reaction conditions. Since the removal of C3H6 is important for the oxidation of CO and C3H6, the catalyst with the highest Pd0 fraction (Pd/0.1Ag-CeO2 and Pd/0.3Ag-CeO2) presented improved catalytic activity. Consequently, the optimal amount of Ag enhanced the OSC of Pd/Ag-CeO2 catalysts and formed active Pd0 species under oxidative conditions, which resulted in the excellent catalytic activity of Pd/Ag-CeO2 for the CO and C3H6 oxidation reaction.
KW - Ag-doped Ceria
KW - CO and CH oxidation
KW - Diesel oxidation catalyst
KW - Palladium
KW - Reducibility
UR - http://www.scopus.com/inward/record.url?scp=85102903997&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2021.125373
DO - 10.1016/j.jhazmat.2021.125373
M3 - Article
C2 - 33765567
AN - SCOPUS:85102903997
VL - 415
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
SN - 0304-3894
M1 - 125373
ER -