Analysing carbon deposition on Ni/YSZ anode tested in an Solid Oxide Fuel Cell (SOFC)

Integrated Planar Solid Oxide Fuel Cells (IP-SOFC), which utilise a Ni/YSZ based anode, have been operated under direct hydrogen-methane mixture fuel injection at 900 oC. This process has shown some disadvantages in fuelling to the IP-SOFC; producing carbon deposition from the methane in the fuel mixture, causing direct structural damage to the IP-SOFC surface and blocking the area of activation for reaction processes and reducing the performances. These factors were shown to adversely affect the performance of the IP-SOFC over time. The aim of this paper is to calculate the amount of carbon deposited through the use of temperature programmed oxidation (TPO). In addition, the distribution of carbon is studied and analysed on all parts of the IP-SOFC cells. The results show that both amorphous and graphitic carbon were formed causing microstructural damage thereby reducing the cell performance. Furthermore, the reaction temperature was demonstrated to increase the total amount of carbon deposition.