Direct carbon fuel conversion in a liquid antimony anode solid oxide fuel cell

Abstract

A direct carbon solid oxide fuel cell (DC-SOFC) with liquid metallic antimony (Sb) anode was assembled. This type of DC-SOFC provides a new way to utilize coal in a both efficient and clean way. The intrinsic reaction kinetics of the liquid Sb anode was closely observed and analyzed without the presence of fuel, and a promotion of cell performance derived from cell discharging was discovered. Then the de-ash coal (ash 2.56wt%) was added in as the fuel, which made the performance of the fuel cell rise dramatically. The interaction between the coal and the Sb based anode under different working temperature was studied, and a conclusion of direct oxidation of carbon at electrolyte-anode interface is drawn from the experimental data. A novel concept of liquid mixed conducting networks is proposed as a reaction mechanism in the anode region for the first time, which involves the interaction among Sb, Sb2O3 (antimony oxide) and coal, perfectly explained the phenomenon observed in the experiment.