Effects of Silver Nanoparticles on the Electrochemical Response of La 0.1 Sr 0.9 TiO 3 Solid Oxide Fuel Cell Anode

Abstract

The effect of the incorporation of silver nanoparticles (Ag-NPs) on theelectrochemical behavior of symmetrical La0.1Sr0.9TiO3 (LST)/ La0.4Ce0.6O2 (LDC)/La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM) cells is presented. Ag-NPs were infiltrated into LSTanodes by using a wet chemical reduction technique. The cells with differentconcentrations of Ag-NPs were prepared by modifying the immersion time in areducing solution. The Ag-NPs infiltrated were characterized by transmission electronmicroscopy (TEM) and scanning electron microscopy (SEM). The analysis of thefraction of AgNPs incorporated into the cells was performed by X-ray diffraction (XRD)and particle-induced X-ray emission (PIXE). The effect of the Ag-NPs on theelectrochemical behavior of the obtained electrodes was studied by electrochemicalimpedance spectroscopy (EIS), varying the hydrogen partial pressure. The EIS spectraobtained were analyzed by the distribution of relaxation times (DRT). The results of thisstudy indicated that the infiltration of Ag-NPs improved the electrochemical response ofthe LST anodes by reducing their ohmic losses due to the increase in electronic conductivity. In this regard, incorporating 16 wt % ofsilver nanoparticles led to a 70% decrease in the area-specific resistance (ASR) of the LST. Furthermore, it was observed that the Ag-NPs infiltrated acted as catalysts of the hydrogen oxidation reaction (HOR), decreasing the overpotential and affecting themechanisms that limit the HOR.