화학공학소재연구정보센터
International Journal of Hydrogen Energy, Vol.43, No.1, 53-63, 2018
Electroless deposition of Co(Mn)/Pd-decorator into Y2O3-stabilized ZrO2 scaffold as cathodes for solid oxide fuel cells
In this work, we show that higher Co or Mn dopant content of up to 25 mol% on Pd can be obtained without modifying the original crystal structure of Pd via co-reduction synthesis route using hydrazine (N2H4), which is not achievable via conventional sol-gel route. The synthesized Co/Mn-doped Pd alloys can inhibit Pd agglomeration that hinders Pd use as an oxygen reduction reaction (ORR) promoter on solid oxide fuel cell (SOFC) cathode. The presence of Co or Mn on Pd lattice of Co/Mn-doped Pd alloy-decorated YSZ (Y2O3 stabilized ZrO2) cathode provides dual advantages of improving the ORR performance of the cathode and enhancing the ORR performance stability during long term operation. Between 600 degrees C and 800 degrees C, Pd0.90Co0.10O-impregnated YSZ cathode displayed the highest ORR performance among PdO-, Pd0.90Co0.10O-, Pd0.75Co0.025O-, Pd0.90Mn0.10O-, and Pd0.75Mn0.25O-impregnated cathodes as indicated by its relatively low area specific resistance of 0.14 Omega cm(2) at 700 degrees C. Our thermal gravimetric analyses and scanning electron microscopy images revealed that the high electrochemical performance stability of Co/Mn-doped Pd alloys during 30 hour cathodic current test correlates with their higher metal <-> metal oxide conversion reversibility and microstructure stability under thermal cycling between room temperature and 900 degrees C (relative to Pd). (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.