Preparation, Characterization and Oxygen Storage Capacity Analysis of La1-XSrXAlO3 Perovskite Materials as Promising Anode for SOFC

Abstract

The Perovskite materials of structure ABO3 are of great interest because their properties can easily be tailored by partial substitution at the A-site, the B-site, or at both A- and B-sites [1]. The partial substitutions at A- and B-sites create structural defects such as oxygen vacancies, which greatly affect properties like electrical conductivity and thermal stability under oxidizing and reducing conditions [2,3,4]. Recent studies have shown that perovskite-like oxides can serve as possible replacements for Ni-based anode materials [5,6], primarily due to their reported coking resistance which is attributed to their high oxygen storage capacity. To develop efficient materials possessing high oxygen storage capacity (OSC) for a number of catalytic applications, and also as anodes for SOFC, A series of Strontium doped LaAlO3 perovskites with formula La1-XSrXAlO3 − δ (x=0–0.10) were prepared by precipitation of nitrate precursors followed by calcination at 800 °C in air for 24h. The material properties of the substituted perovskites were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) analyses, Raman Spectroscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The doped materials exhibited a single perovskite phase in air up to the Sr doping of 0.4 mole % which was revealed from XRD and Raman analysis. The redoxability and size of the dopants were proposed to play a pivotal role in enhancing the OSC of the as-prepared materials. In this context, the oxidation state of a dopant located at the surface was determined by XPS, Soot oxidation experiments were further performed to examine the relative OSC of the La1-XSrXAlO3 − δ based solid solutions and revealed that soot oxidation activities increased till the Sr doping of .05 mole% when compared to undoped LaAlO3. These results clearly shows that La1-XSrXAlO3 − δ materials can be used as anode for SOFC. References M.A. Pena, J.L.G. Fierro, Chem. Rev. 101 (2001) 1981.Y. Itagaki, M. Mori, Y. Hosoya, H. Aono, Y. Sadaoka, Sens. Actuators, B 122 (2007) 315.Q.T. Wei, R.S. Guo, F.H. Wang, H.L. Li, J. Mater. Sci. 40 (2005) 1317.H. Ulmann, N. Trofimenko, F. Tietz, D. Stover, A. Ahmad-Khanlou, Solid State Ion. 138 (2000) 79.S.P. Jiang, X.J. Chen, S.H. Chan, J.T. Kwok, J. Electrochem. Soc. 153 (2006) A580.S. Tao, J.T.S. Irvine, Chem. Rec. 4 (2004) 83.