Mobility and reactivity of lattice oxygen in Gd-doped ceria promoted by Pt

Abstract

For samples of the Ce 1-x Gd x O 2-y system prepared by the Pechini route and promoted with Pt, the mobility and reactivity of lattice oxygen were found to correlate with the density of surface and bulk anion vacancies.

Effect of the lattice oxygen mobility on the activity of Gd-doped ceria promoted with pt in syngas generation from methane at short contact times

“…Details of sample preparation by the Pechini route and their characterization are given in [6]. The catalytic activity of the samples was tested in the reactions of POM (feed, 1% CH 4 + 0.5% O 2 in He), steam (feed, 1% CH 4 + 1% H 2 O in He) and dry (feed, 1% CH 4 + 1% CO 2 in He) reforming of methane at short contact times (1.25-108 ms).…”

“…After the standard pretreatment in O 2 at 500°C, cooling to 25°C and switching to a required feed, the temperature was increased from 25 to 880°C with the rate 5°C/min. In some cases, to check the effect of deep reduction of the samples by methane on their activity, catalytic reactions have been carried out after a TPR run in the presence of CH 4 [6]. In some experiments, consecutive temperatureprogrammed runs of steam and dry reforming were alternated with sample reoxidation in O 2 at 500°C.…”

“…40%) and the selectivity toward syngas, which suggests the predominance of the consecutive route in the selective oxidation of methane [3]. However, for the samples with a higher content of Gd (Pt/Ce 0.6 Gd 0.4 O 2-y ) and, hence, a lower lattice oxygen mobility [6], the effect of the contact time is much less pronounced (Fig. 4).…”

“…In our previous paper [6], mobility and reactivity of the lattice oxygen of Pt/Ce 1-x Gd x O 2-y samples were estimated and compared with their bulk and surface composition and their structural features. The aim of this paper is to elucidate the effect of the lattice oxygen mobility on the catalytic activity in the generation of the synthesis gas from methane by partial oxidation, steam and dry reforming of methane.…”

Design and characterization of LSM/ScCeSZ nanocomposite as mixed ionic–electronic conducting material for functionally graded cathodes of solid oxide fuel cells

“…For series of samples of Gd-doped ceria with Gd content in the range of 5-50 at.%, the dynamic extent of exchange was shown to correlate with the ionic conductivity of these electrolytes controlled by the oxygen diffusion [27].…”