Synthesis of La1-xSrxAlO3 Perovskites by Reverse strike Co-Precipitation Method and its Soot Oxidation activity

Document Type: Research Article

Authors

1 Department of Chemical Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Karnataka, 576104, INDIA

2 Department of Chemical Engineering, Indian Institute of Technology, Guwahati, Assam, 781039, INDIA

Abstract

Perovskite series La1-xSrxAlO3 (x=0 to 0.4) materials were synthesized by reverse strike co-precipitation route and their soot oxidation activity was evaluated. All the catalysts synthesized were characterized using XRD, BET specific surface area, FESEM and XPS techniques. As analyzed by XRD, La1-xSrxAlO3 perovskite from x=0 to 0.35 showed the formation of rhombohedral phase, while for La0.6Sr0.4AlO3 sample the secondary phases of SrO, La2O3, and Al2O3 were also noticed. Sr-doped samples exhibited higher BET specific surface area when compared to pure LaAlO3. FESEM analysis showed that there is a change in morphology upon doping of Sr into LaAlO3. The O1s spectra observed from XPS analysis showed that amongst the series of samples synthesized, La0.75Sr0.25AlO3 contained higher amounts of adsorbed oxygen. It can also be noted from XPS analysis that in all the Sr-doped samples, La, Sr, and Al existed in +3, +2 and +3 oxidation states respectively. Soot oxidation analysis showed that La0.75Sr0.25AlO3 exhibited higher catalytic activity relative to other catalysts due to enhanced amount of reactive adsorbed oxygen species.

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