Catalytically Active and Carbon-Resistive Anode Catalyst for Solid-Oxide Fuel Cells Operated at Low Temperatures (500-600 °C)

Thedevelopment of active catalysts is always challenging in thefield of energy devices. In this work, Li-doped, Ni-Cu-based,and Ni-free nanocomposite anode catalysts are synthesized and studiedfor solid-oxide fuel cells (SOFCs) operated at a low temperature usinghydrogen and biogas as fuels. The catalysts with compositions Ni0.6Li0.2Cu0.2-oxide/La0.2Ce0.8O2-delta (NLC622-LDC), Ni0.2Li0.2Cu0.6-oxide/La0.2Ce0.8O2-delta (NLC226-LDC), and Ni0.0Li0.2Cu0.8-oxide/La0.2Ce0.8O2-delta (NLC028-LDC) are synthesized using the glycerol-assistedgel combustion route (GGCR). The structural analysis revealed thecubic structure of metallic oxide materials such as NiO and CuO phaseswhile the cubic fluorite structure of CeO2 as an ionicoxide phase. The optical band gaps (E (g)'s) of anode catalysts NLC622-LDC, NLC226-LDC, and NLC028-LDCare found to be 2.08, 2.29, and 2.37 eV, respectively. Furthermore,the anode catalyst with a higher nickel concentration shows betterelectrical conductivity and a lower activation energy of 3.47 S cm(-1) and 0.67 eV at 600 degrees C, respectively, as comparedto those of a nickel-free anode catalyst with lower nickel content.The electrochemical behavior of nanocomposites is studied at 600 degrees Cusing Nyquist plots. Electrochemical impedance analysis is carriedout to see the effect of hydrocarbon fuel like biogas at the anodeside. Finally, the electrochemical performance of NiLiCu-LDC catalyst-basedfuel cells is tested under hydrogen and biogas fuels. Overall, thefuel cell based on the NLC622-LDC anode catalyst has higher OCV andpower density with both fuels, hydrogen and biogas. Therefore, NLC622-LDCis a highly catalytically active anode catalyst which demonstratedsignificantly better performance for SOFCs operated at a low temperature(500-600 degrees C) without any carbon resistance.