Faculty Publications
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Item Studies on the Solid Oxide Cell Perovskite Electrode Materials for Soot Oxidation Activity(Springer, 2019) Shenoy, C.S.; Patil, S.S.; Govardhan, P.; Shourya, A.; Prasad Dasari, H.P.; Saidutta, M.B.; Harshini, H.Solid oxide cell (SOC) perovskite electrode materials (BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3-?), LSCF (La0.6Sr0.4Co0.2Fe0.8O3-?) and LSCM (La0.75Sr0.25Cr0.5Mn0.5O3-?)) were synthesised using microwave-assisted reverse-strike co-precipitation method and tested for soot oxidation activity. The calcined perovskite materials were characterized using FT-IR, XRD, SEM and BSE, BET and BJH and XPS analysis. The mean activation energy for soot oxidation was calculated from Ozawa plots at various heating rates (5, 10, 15 and 20 K/min) at different levels of soot conversions (T10 to T90) for BSCF, LSCM and LSCF perovskite materials and was around 133 ± 11.5, 138 ± 9.9 and 152 ± 7.2 kJ/mol, respectively. Irrespective of the heating rates, BSCF material showed the lowest T50 temperature than compared to other samples, and it is correlated to the presence of Fe3O4 as a secondary phase. © 2019, Springer Nature Switzerland AG.Item Effect of fuel and solvent on soot oxidation activity of ceria nanoparticles synthesized by solution combustion method(KeAi Communications Co., 2019) Patil, S.S.; Prasad Dasari, H.P.Effect of fuel (glycine and urea) and solvent (water, acetone and ethanol) on the soot oxidation activity of ceria nanoparticles synthesized by solution combustion method is carried out in the present study. X-ray diffraction (XRD) patterns displayed a fluorite structure and the Tauc's plot obtained from UV-Diffusive Reflectance spectroscopy (UV-DRS) showed that the band gap value was around 2.9–3.1 eV for the synthesized ceria nanoparticles irrespective of the fuel and solvent used. Ceria nanoparticles synthesized using glycine and acetone resulted in lower crystallite size, higher facet ratios ([1 0 0]/[1 1 1] and [1 1 0]/[1 1 1]) and higher lattice strain than compared to other solvents and fuels and thus resulted in better soot oxidation activity (T50 = 416 °C). The present synthesis method has played a significant role in improving the reactive facet ratios, providing lower crystallite size and high lattice strain. © 2019Item Effect of morphology and oxidation state of nickel on diesel soot oxidation activity(Elsevier Ltd, 2022) Vijay, M.P.A.; Patil, S.S.; Madhura, D.R.; Anjana, A.P.; Gouramma, P.; Prasad Dasari, H.P.; Arya, S.B.; Harshini, H.NiO sample is synthesized using the EDTA citrate complex method and calcined at 600 °C/5 h. Ni sample was acquired by reducing NiO to Ni at 600 °C in 4% H2/N2 atmosphere. Its physicochemical properties were obtained by XRD and Raman spectroscopy analysis, where it confirmed the complete reduction of NiO to Ni. SEM and TEM micrographs revealed a drastic particle growth for the Ni, indicating NiO sintering during the reduction process and a considerable surface morphology change. Ozawa and KAS methods were used to calculate the mean activation energy (Ea) value. NiO displayed lower Ea than Ni. Hence, NiO showed better catalytic activity than Ni. © 2022Item Printex-U soot oxidation kinetic behaviour over Alumina and Quartz(Elsevier Ltd, 2022) Ganiger, S.; Patil, S.S.; Prasad Dasari, H.P.; Priyanka, R.; Kollimarla, S.Printex-U carbon (Pure Soot, S0) on alumina (SA) and quartz (SQ) powder were considered to understand the behaviour of oxidation reaction and kinetic analysis. A similar model of the single-step reaction was followed by the Soot (S0) and SA sample, while SQ followed a complex mechanism of multiple-step reactions. From the experimental and theoretical calculations, it was observed that there was a slight decrease in the T50 temperature for SA, which also had the lowest Ea, but there was an increase in T50 and Ea for SQ compared to the S0 sample. From the present study, it can be understood that the alumina enhanced the catalytic activity when compared to pure soot alone, whereas quartz inhibited the activity. The T50 temperature, Ea, and A calculated were obtained in SA < S0 < SQ. The soot properties and their kinetics will further help to design catalyzed diesel particulate filters. © 2021 Elsevier LtdItem A Negative Effect of Niobium-Doped Ceria on Soot Oxidation Activity‡(John Wiley and Sons Inc, 2022) Patil, S.S.; Naik, S.; Ramesh, M.D.; Harshini, H.; Prasad Dasari, H.P.Niobium-doped ceria catalysts were synthesized to study soot oxidation activity. X-Ray diffraction (XRD) and Raman analysis of the samples revealed the presence of a fluorite structure of CeO2 for all the doped samples. The T50 temperature of the pure CeO2 sample was more significant than that of bare soot. The high catalytic activity of the CeO2 catalyst can be attributed to the low crystallite size, high facet ratio, and the large Brunauer-Emmett-Teller (BET) surface area as compared to Nb-doped samples. The activation energy calculated by both Ozawa and KAS methods were found to be low for CeO2 when compared to Nb-doped samples. CeO2 resulted in better soot oxidation activity with low activation energy. © 2022 Wiley-VCH GmbHItem An investigation on copper-loaded ceria-praseodymium catalysts for soot oxidation activity and its kinetics(Springer Science and Business Media Deutschland GmbH, 2024) Patil, S.S.; Prasad Dasari, H.P.The Cu-loaded Ce-Pr catalyst series was successfully developed to study their performance on soot oxidation activity and its kinetic behavior. The doped samples showed a similar trend for cubic fluorite structure except for CuO, which possessed a monoclinic structure from the XRD analysis. Facet ratios [{100}/{111} and {110}/{111}] for the reactive planes were calculated from XRD spectra; the ratio was high for the 5 Cu-CP catalysts. The oxygen vacancy peaks were noticed from Raman spectra for the doped samples. 5 Cu-CP displayed the better catalytic activity of T50 = 402 °C, which may be attributed to high reactive planes and better reducibility. The addition of Cu showed a slight enhancement in catalytic activity compared to CP and pure Ce. The kinetic triplets were evaluated: the activation energy (Ea), pre-exponential factor (A), and the reaction model. Pure Ce displayed the lowest Ea and A values, whereas pure Cu showed high Ea and A values by all the methods. Graphical abstract: (Figure presented.) © The Author(s) under exclusive licence to Associação Brasileira de Engenharia Química 2023.Item Study of CO oxidation activity of NiO-PDC and NiO-YSZ catalysts coated on alumina wash-coated honeycomb cordierite monolith(Springer Science and Business Media Deutschland GmbH, 2025) Wagay, A.A.; Shourya, A.; Patil, S.S.; Shirasangi, R.; Prasad Dasari, H.P.In this study, the EDTA-Citrate method was employed to synthesize NiO-PDC (NPC) and NiO-YSZ (NYZ) powder catalysts in nanostructured form. Subsequently, the catalysts were slurry dip-coated onto monolith cordierite substrates with alumina, using a one-step coating approach, and their CO oxidation activity was tested. The coating was achieved by first mixing the catalyst with the alumina suspension to prepare a homogeneous slurry, which was then used for dip coating onto the monolith. The adherence test was performed on the coated monolith to evaluate the mechanical stability of the catalyst-alumina composite layer. The coating was visually confirmed through optical imaging. The remaining powders (after coating) were then subjected to BET surface area, XRD, Raman spectroscopy, H2 TPR and O2 TPD analysis for characterization. Raman spectra showed that NPC exhibited higher oxygen vacancies than NYZ. H2 TPR and O2 TPD provided better evidence of the reduction potential and O2 desorption of NPC respectively. NPC/cord demonstrated the highest catalytic activity (T50 = 165 °C) compared to NYZ/cord (T50 = 215 °C) and bare cordierite (T50 = 777 °C), which is attributed to its better redox properties and higher oxygen vacancies. The effect of flow rate and heating rate on CO oxidation was studied on NPC/cord and NYZ/cord. The long-term stability of the NPC/cord and NYZ/cord were tested through 5-h and 50-h isothermal studies. © The Author(s) under exclusive licence to Associação Brasileira de Engenharia Química 2025.