Durable and High-Performance Direct-Methane Fuel Cells with Coke-Tolerant Ceria-Coated Ni Catalysts at Reduced Temperatures

Natural gas constitutes a promising energy source in the intermediate future because of the existing supply infrastructure and ease of storage and transportation. Although a solid oxide fuel cell can directly convert chemical energy stored in the hydrocarbon fuel into electrical energy at high temperatures, carbon formations on the nickel-based anode surfaces cause serious degradation of the long-term performance. Here, we report highly coke-tolerant ceria-coated Ni catalysts for low-temperature direct-methane fuel cells. The catalyst shows the high activity for CO oxidations, which is beneficial to avoid carbon formations induced by CO disproportionation at low temperatures. When the ceria-coated Ni catalysts were applied to the solid oxide fuel cells as a catalyst layer, the cell generates a power output of 1.42 W cm^-2 at 610 °C in dry methane and operates over 1000 h at a current density of 1.2 A cm^-2.