TY - JOUR
T1 - Enhanced oxygen storage capacity of Ce0.65Hf0.25M0.1O2-δ (M=rare earth elements)
T2 - Applications to methane steam reforming with high coking resistance
AU - Harshini, D.
AU - Lee, Dae Hyung
AU - Jeong, Jihoon
AU - Kim, Yongmin
AU - Nam, Suk Woo
AU - Ham, Hyung Chul
AU - Han, Jong Hee
AU - Lim, Tae Hoon
AU - Yoon, Chang Won
N1 - Funding Information:
This research was supported by the Global Research Laboratory Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning of Republic of Korea. Part of this research was also supported by the Fundamental Technology Development Programs for the Future through the Korea Institute of Science and Technology.
PY - 2014/4/27
Y1 - 2014/4/27
N2 - To develop efficient materials possessing high oxygen storage capacity (OSC) for a number of catalytic applications, ceria-hafnia based metal oxides, Ce0.65Hf0.25M0.1O2-δ, (CH-M, M=Tb, Sm, Nd, Pr, and La), were prepared by the EDTA-citrate method. The structural and textural properties of the as-synthesized materials were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analyses, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and high resolution transmission electron microscopy (HRTEM). These analyses indicated that the doping of the rare earth elements could potentially induce enhanced OSC compared to the undoped CeO2-HfO2 solid solution, and particularly, the CH-Pr, CH-La, and CH-Tb materials were suggested to possess greater OSC than other CeO2-HfO2 based solid solutions. The redoxability and size of the dopants were proposed to play a pivotal role in enhancing the OSC of the as-prepared materials. Soot oxidation experiments were further performed to examine the relative OSC of the ceria-hafnia based solid solutions and revealed that soot oxidation activities increased in the order of CH-Pr>CH-La>CH-Tb>CH-Nd>CH-Sm>CH (undoped material). To elucidate the effect of these materials on suppressing carbon coking, Ni/CH and Ni/CH-Pr catalysts were synthesized by a solvothermal method and their catalytic activities towards steam reforming of methane with steam to carbon ratios of 1-2 at 700°C were carried out. The Ni/CH-Pr catalyst exhibited superior activity and stability over Ni/CH for the steam reforming of methane, which likely resulted from the enhanced oxygen mobility of the CH-Pr support.
AB - To develop efficient materials possessing high oxygen storage capacity (OSC) for a number of catalytic applications, ceria-hafnia based metal oxides, Ce0.65Hf0.25M0.1O2-δ, (CH-M, M=Tb, Sm, Nd, Pr, and La), were prepared by the EDTA-citrate method. The structural and textural properties of the as-synthesized materials were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analyses, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and high resolution transmission electron microscopy (HRTEM). These analyses indicated that the doping of the rare earth elements could potentially induce enhanced OSC compared to the undoped CeO2-HfO2 solid solution, and particularly, the CH-Pr, CH-La, and CH-Tb materials were suggested to possess greater OSC than other CeO2-HfO2 based solid solutions. The redoxability and size of the dopants were proposed to play a pivotal role in enhancing the OSC of the as-prepared materials. Soot oxidation experiments were further performed to examine the relative OSC of the ceria-hafnia based solid solutions and revealed that soot oxidation activities increased in the order of CH-Pr>CH-La>CH-Tb>CH-Nd>CH-Sm>CH (undoped material). To elucidate the effect of these materials on suppressing carbon coking, Ni/CH and Ni/CH-Pr catalysts were synthesized by a solvothermal method and their catalytic activities towards steam reforming of methane with steam to carbon ratios of 1-2 at 700°C were carried out. The Ni/CH-Pr catalyst exhibited superior activity and stability over Ni/CH for the steam reforming of methane, which likely resulted from the enhanced oxygen mobility of the CH-Pr support.
KW - Ceria-Hafnia
KW - Coking resistance
KW - Oxygen storage capacity
KW - Rare earth element
KW - Steam reforming of methane
UR - http://www.scopus.com/inward/record.url?scp=84889687242&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2013.11.022
DO - 10.1016/j.apcatb.2013.11.022
M3 - Article
AN - SCOPUS:84889687242
SN - 0926-3373
VL - 148-149
SP - 415
EP - 423
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
ER -