Faculty Publications
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Item Promotional effect of nickel addition on soot oxidation activity of Ce0.9Pr0.1O2 oxide catalysts(Springer, 2020) Rajvanshi, K.; Patil, S.S.; Lakhanlal, u.; Prasad Dasari, H.P.; Saidutta, M.B.; Harshini, H.The present study investigates the promotional effect of Ni addition on soot oxidation activity of Ce0.9Pr0.1O2 oxide catalysts. A series of xNi-PDC (x= 0, 3, 5, 7, 10, 15, and 20 mol%) catalysts were synthesized by solution combustion synthesis method and characterized by XRD, Raman spectroscopy and TEM analysis. XRD and SAED patterns of the catalysts show cubic fluorite structure of ceria with an average crystallite size of 6–8 nm, and only 20Ni-PDC display NiO as a secondary phase. Raman spectra of xNi-PDC catalysts display an increase in oxygen vacancies. With a minimum addition of 10 mol% Ni to PDC, i.e., the 10Ni-PDC catalyst showed optimum soot oxidation activity (T50 = 360 °C) than compared to PDC and other Ni-PDC catalysts. Lattice strain and oxygen vacancies played a key descriptor role in showing better soot oxidation activity of the 10Ni-PDC catalyst. From the soot oxidation kinetic studies, the activation energy obtained by Ozawa plots for the 10Ni-PDC catalyst is 137 kJ/mol. © 2020, Institute of Chemistry, Slovak Academy of Sciences.Item Electrical conductivity studies on LAMOX based electrolyte materials for solid oxide fuel cells(Elsevier Ltd, 2022) Srijith; Lakhanlal, u.; Das, A.; Prasad Dasari, H.P.; Saidutta, M.B.In this study, the electrical conductivity of the LAMOX based electrolytes (La1.8Dy0.2Mo2-xWxO9 (x = 0, 0.1, 0.2, 0.5, and 1), and La1.8Dy0.2Mo2-xGaxO9 (x = 0.1)) synthesized by the citrate complexion method has been studied using DC four-probe method. The electrical conductivity of the electrolytes is measured in the temperature range of 800–400 °C in the air (∼100 ml min−1). The effect of W and Ga substitution at the Mo site on the electrical conductivity is evaluated. The long-term electrical conductivity stability test (time on stream) (5 h) is conducted at 650, 580, and 520 °C to study the effect of possible phase transition on electrical conductivity. A high-temperature XRD study is also conducted in the temperature range of 500–650 °C (during heating and cooling) on selected electrolyte materials (La1.8Dy0.2Mo2-xWxO9 (x = 0 and 0.1) and La1.8Dy0.2Mo2-xGaxO9 (x = 0.1)) to study the α↔β phase transition. The electrical conductivity of these electrolytes in the air at 800 °C is in the range of 5.3 × 10−2 – 14 × 10−2 S cm−1. The activation energy (EA) of these electrolytes is in the range of 1.11–1.62 eV. The VTF parameters σo, B, and To are in the range of 67.46–395.88 S cm−1 K0.5, 0.122–0.254 eV, and 247–347 °C, respectively. The La1.8Dy0.2Mo2-xWxO9 (x = 0.1) shows highest electrical conductivity (14 × 10−2 S cm−1, EA = 1.54 eV) among all electrolytes in air at 800 °C and for this material the VTF parameters σo, B, and To are 170.32 S cm−1 K0.5, 0.153 eV, and 302 °C, respectively. © 2022 Elsevier Ltd and Techna Group S.r.l.