Enhanced Stability and Catalytic Activity on Layered Perovskite Anode for High-Performance Hybrid Direct Carbon Fuel Cells

In this work, we investigate a novel A-site ordered layered perovskite oxide, (PrBa)_0.95Fe_1.8-xCu_xNb_0.2O_5+δ (PBFCN), as an anode material for hybrid direct carbon fuel cells (HDCFCs). We study the effect of anode composition on the electrochemical performance of HDCFCs. The electrolyte-supported single cell with (PrBa)_0.95Fe_1.4Cu_0.4Nb_0.2O_5+δ (PBFCu_0.4N) anode achieves the highest peak power density of 431 mW cm^-2 at 800 °C with activated carbon as the fuel. Moreover, a power generation unit is also made to demonstrate the practical utilization of PBFCN, which delivers a peak power of 0.51 W at 800 °C without any carrier gas, and a small fan can operate for more than 10 h by using the as-fabricated HDCFC as a power generation unit. The PBFCN anode achieves greatly enhanced catalytic activity by improving the chemical adsorption and electrochemical oxidation of CO at the anode/CO interface, which is mainly due to the high-activity Cu ions in PBFCN. The inactive element Nb doping and ordered layered structure endow the material with excellent redox structural stability. The present study provides a new idea for the design and development of high-performance anode materials for HDCFCs applications.