Nickel/gadolinium-doped ceria anode for direct ethanol solid oxide fuel cell

Abstract

This report investigates the properties of nickel/gadolinium-doped ceria (Ni/GDC) as anode material for bio-ethanol fueled SOFC. The Ni/GDC cermets with 18 and 44 wt.% Ni were prepared by a hydrothermal method. Ethanol decomposition, steam reforming, and partial oxidation of ethanol were studied using a fixed-bed reactor at 1123 K. Carbon was formed only under dry ethanol for both catalysts. The addition of water or oxygen to the feed inhibited the formation of carbon. Ni/GDC was used as the anode current collector layer and as a catalytic layer in single cells tests. No deposits of carbon were detected in single cells with Ni/GDC catalytic layer after 50 h of continuous operation under direct (dry) ethanol. This result was attributed to the catalytic properties of the Ni/GDC layer and the operation mechanism of gradual internal reforming, in which the oxidation of hydrogen provides the steam for ethanol reforming, thus avoiding carbon deposition.