Steam Reforming Catalytic Layer on Anode-Supported and Metal-Supported Solid Oxide Fuel Cells for Direct Ethanol Operation

Abstract

A catalyst based on lanthanum chromite with exsolved metallic ruthenium nanoparticles (LaCrO3-Ru) was applied as a catalytic layer for internal ethanol steam reforming of anode-supported and metal-supported solid oxide fuel cells. Both the cermet anode and the metal supports exhibit limited catalytic properties for the ethanol steam reforming reaction. Thus, the LaCrO3-Ru catalysts were optimized for operating temperatures in the 600-700 °C range to promote stable ethanol reforming. The microstructure of the deposited catalytic layer was controlled using pore formers with low burnout temperature, and sintering of the catalytic layer was done in situ during cathode sintering of the metal-supported fuel cell. The performance of the fuel cells was evaluated at 700 °C under hydrogen, anhydrous ethanol, and water/ethanol mixtures. The LaCrO3-Ru catalytic layer had no significant impact on the electrochemical properties of the fuel cells, and samples with the catalytic layer or without it exhibited similar performance in hydrogen. Nonetheless, initial durability tests have shown that the catalytic layer plays a crucial role in the stability of both the anode and the metal-supported fuel cells under ethanol.