Catalytic properties of monometallic copper and bimetallic copper-nickel systems combined with ceria and Ce-X (X = Gd, Tb) mixed oxides applicable as SOFC anodes for direct oxidation of methane

摘要

The present contribution analyses the possibilities of both Cu and bimetallic Cu-Ni formulations combined with CeO_2-based oxides for their use as anodes of solid-oxide fuel cells (SOFC) for direct oxidation of methane. The main objective is related to examining how the metals combination and the presence of dopants like Gd and Tb into the ceria structure could affect the catalytic activity of this type of materials towards reaction with methane. For this purpose, cermets of Cu alone as well as bimetallic Cu-Ni (with 20 and 40 wt.%) have been synthesised in combination with various supports composed by oxides of Ce, Ce-Tb and Ce-Gd. The behaviour of such systems towards interaction with dry methane up to 900℃ was analysed by means of CH_4-TPR tests. Appreciable differences in the catalytic activity are revealed as a function of the presence of nickel as well as Gd or Tb dopants in the systems. The characteristics of carbonaceous deposits formed upon such interaction was analysed by means of TPO and XPS.