RT journal article
T1 Physicochemical properties of nanostructured Pd/ lanthanide-doped ceria spheres with high catalytic activity for CH4 combustion
A1 Óscar Fuentes, Rodolfo
A1 Acuña, Leandro M.
A1 Leyva, A. Gabriela
A1 Baker, Richard T.
A1 Pan, Huiyan
A1 Chen, Xiaowei
A1 Delgado Jaén, Juan José
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
K1 CH4 combustion
K1 Pd
K1 La-modfied ceria nanosphere
AB In this work, nanostructured Ce0.9Gd0.1O2 d (GDC) and Ce0.9Pr0.1O2 d (PrDC) spheres previously obtainedby microwave assisted hydrothermal homogeneous co-precipitation were impregnated with 1 wt% Pd bythe incipient wetness impregnation by an aqueous Pd2+ solution. Their properties were characterized bysynchrotron radiation X-ray diffraction (SR-XRD), X-ray absorption near-edge spectroscopy (XANES) andscanning and high resolution electron microscopy with X-ray spectroscopy. Spherical particles withaverage diameters around 200 nm were found to consist of crystallites of average size, 10 nm, withsmall particles of PdO finely dispersed over the sphere surface. In situ XRD and XANES experiments werecarried out under reducing and oxidizing conditions in order to investigate the redox behaviour of thesematerials and to evaluate the effect of Pd loading on the oxidation state of Ce. All of the lanthanidedopedceria (LnDC) supports were found to have a cubic crystal structure (Fm3m space group). Anincrease in lattice parameters was observed under reducing conditions which was attributed to thereduction of Ce4+ ions to the larger Ce3+ ions, and to the associated increase in oxygen vacancy (VO)concentration. Addition of Pd to the LnDC spheres increased their Ce3+ content. Finally, catalytic testsfor CH4 combustion were performed on the LnDC and Pd/LnDC nanocatalysts. The best performancewas observed in samples with 1 wt% Pd loading, which exhibited T50 values (temperature at which 50%of CH4 conversion was reached) close to 310  C. These values are 220  C and 260  C lower than thoseobtained for nanostructured PrDC and GDC spheres alone, respectively.
PB RSC
SN 2050-7496
YR 2018
FD 2018-03-29
LK http://hdl.handle.net/10498/30965
UL http://hdl.handle.net/10498/30965
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 12-nov-2026