Performance of SOFC Power Unit Assisted by Paper-Structured Catalyst

This study aims at the performance enhancement of direct internal reforming (DIR)-SOFC. Paper-structured catalyst (PSC) is a flexible catalyst material composed of inorganic fiber network loaded with metal catalyst which can be applied into cell stack to assist hydrocarbon reforming. Catalytic performance of PSC was considerably improved by the dispersion of Mg/Al hydrotalcite (HDT) in the inorganic fiber network to have higher tolerance to fuel impurity (sulfur) poisoning because of the formation of fine Ni particles and suppression of Ni loading on the inorganic fiber (SiO₂-Al₂O₃) to cause coking.

High temperature SOFCs can convert chemical energy of a fuel directly to electricity even in the feed of low calorie gas. The use of engine-exhaust, which is most accessible lean gas, as a fuel for SOFC is promising idea. Recently, a compact SOFC unit operated by the direct feed of engine-exhaust was developed by Atsumitec Co., Ltd. However, performance of the DIR-SOFC unit can easily deteriorate, unless fuel is homogeneously supplied into the unit in which several numbers of stacks were arrayed. This study demonstrated that insertion of the HDT-dispersed PSC into the real SOFC stack between the cells led to 36 % increase in the performance because PSCs can boost up the output power of stacks placed at the positions where fuel is not well supplied.