Partial oxidation of methane into syngas on Pt-supported mixed oxides: effect of surface/lattice oxygen mobility in complex oxides on the kinetic features of the reaction and performance stability

Abstract

INGENIERIE+ABB:CMI:EGUNon

Dry reforming of methane over fluorite-like mixed oxides promoted by Pt

“…It increases the concentration of oxygen vacancies and the surface oxygen mobility and, as a result, increases the rate of transformation of adsorbed CH x species into CO and H 2 at the Pt-support interface. As for the same catalysts in POM, the apparent first-order rate constants of the methane transformation in DR were estimated for all three catalysts using the model of a plug-flow reactor [5,6]. Comparison of these values revealed that the constants of DR are several times lower than those of POM (Table 1).…”

“…The basic characteristics of active components, procedures of their supporting on separate corundum channels and experimental features were described in detail earlier [5][6][7]. The catalytic activity in DR was measured at atmospheric pressure in the temperature range from 600 to 850°C, and at contact times in the range from 4.7 to 15.0 ms.…”

“…Hence, the oxygen mobility in the support and the Pt-support interaction appear to be important factors that provide the efficient and stable performance of Pt-based catalysts in this reaction. Previously, we investigated the activity and selectivity of Pt-supported PrCeZrO, GdCeZrO and LaCeZrO catalysts in the partial oxidation of CH 4 at millisecond contact times [5,6]. Their catalytic performance was shown to depend strongly on the Pt-support interaction and surface/bulk oxygen mobility controlled by the chemical composition of oxides, catalysts pretreatment and process parameters.…”

“…Their catalytic performance was shown to depend strongly on the Pt-support interaction and surface/bulk oxygen mobility controlled by the chemical composition of oxides, catalysts pretreatment and process parameters. Secondary reactions of steam (SR) and dry (DR) reforming make a considerable contribution to the partial oxidation of methane (POM) mechanism at higher temperatures and longer contact times [5,6]. Therefore, these catalysts could be attractive as model systems to verify the effect of oxygen mobility in the complex oxide support on the activity and stability of supported Pt in the dry reforming of methane.…”