Catalytic studies on ceria lanthana solid solutions II. Oxidation of carbon monoxide

Carbon dioxide reduction on gadolinia-doped ceria cathodes

“…The low frequency semicircular arc increases in size with lower CO/CO 2 ratio; which is consistent with observations by Mizusaki et al [10] on Pt/YSZ/Pt cells, and Lauvstad et al [11] on SrFeO 3 /YSZ cells, in a similar range of CO/CO 2 gas mixtures. There is evidence that the CO oxidation reaction rate on ceria [46,47] and other oxide catalysts is reduced when the reactant gas contains CO 2 . This may be due to preferential adsorption, or a higher activation energy of desorption of CO 2 , on the active catalyst sites of oxide and noble metal catalysts [As an aside, Shao and Haile [48] have reported reduced oxygen reduction reaction rates on a promising oxide cathode material, Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3 − δ (BSCF), in O 2 gas mixtures with CO 2 concentrations as low as 5%].…”

Hydrogen production by steam reforming of ethanol over Co3O4/La2O3/CeO2 catalysts synthesized by one-step polymerization method

“…The average crystallite sizes of catalysts were calculated using the principal peak for CeO 2 (2Â = 28.6 • ) and for Co 3 O 4 (2Â = 36.94 • ) by using the Sherrer formula [35]; the lattice parameters were also calculated, all these values are shown in [38][39][40]. This result suggests that La 2 O 3 is highly dispersed in the catalyst; or is segregated forming very small particles which are not detected by XRD [41,42]. The formation of perovskite phase with a rhombohedral structure (LaCoO 3 ) was not observed in the samples containing 4%, 8% and 12% of La 2 O 3 , this phase together with Co 3 O 4 phase were observed only in sample CoLa (see Fig.…”

“…2b), indicating that La 3+ cations substituted some Ce 4+ in the CeO 2 crystal lattice [41,42]. This conformation is possible since these cations have very close ionic radii (La 3+ = 1.06Å and Ce 4+ = 0.94Å [44]) and the respective oxides have very close bond sizes (Ce O = 2.34Å [45] and La O = 2.56Å [46]).…”

The Effect of Precipitants on Ce-La Solid Solution Prepared from Mixed Rare Earth Chloride by a Co-Precipitation Method

“…The oxygen vacancies also helped ceria to create a strong metal-support interaction, and promote the dispersion of noble metals [19,20]. Comparing to pure ceria, the advantage of CL were found in many catalytic applications, for example soot oxidation [6,21], CO oxidation [22][23][24], methane oxidation [25,26], steam reforming of methane [27] and water-gas shift reaction [28][29][30].…”