http://nopr.niscpr.res.in/handle/123456789/59185 2026-10-11T07:01:54Z http://nopr.niscpr.res.in/handle/123456789/59197 Title: Comparison study of preferential oxidation of CO over nanocrystalline Cu/CeO2 catalysts synthesized by different preparation methods Authors: Adak, Shubhadeep; Ahmad, Md Sarfaraz; Sadhu, Souvik; Khatun, Rubina; Prasad, V V D N; Bal, Rajaram Abstract: Preferential oxidation of carbon monoxide in presence of excess hydrogen is a promising alternative to restrict the CO deposition in the Pt-anode in the practical polymer electrolyte membrane fuel cell application. In the present work, nanocrystalline copper-ceria catalysts have been synthesized by hydrothermal method, wet impregnation method and urea nitrate combustion method. Their characterizations have been carried out by using X-ray diffraction, transmission electron microscopy, X . ray photoelectron spectroscopy- It has been found that Cu2+ replaced Ce4+ in cerium oxide, creating oxygen vacancy. The formation of more nano-sized CeO2 leads to more oxygen vacancies in CeO2 through the formation of interfacial Cu1+ ions, which also enhances the CO oxidation activity. Among the synthesized Cu-CeO2 catalysts, the catalyst prepared by hydrothermal method have shown both CO conversion andC O2 selectivity as 100% towards CO oxidation at 373 K in the presence of excess H2 making this catalyst viable for practical fuel cell application.. Page(s): 121-126 2022-02-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/59196 Title: Unveiling the reactions of triethylphosphite and its diethylamino substituted derivatives to carbon tetrachloride with a molecular electron density theory perspective Authors: Barhoumi, Ali; Salah, Mohammed; Zeroual, Abdellah; Chakraborty, Mrinmoy; Acharjee, Nivedita Abstract: A molecular electron density theory study is presented herein for the reactions of triethylphosphite (TEP) and its diethylamino substituted derivatives (DEAP and MEAP) to carbon tetrachloride (CCl4). Analysis of the Electron localization function (ELF) has allowed characterizing the electronic structure of the reagents and the conceptual density functional theory (CDFT) study predicted the polar character of the reactions with the electronic flux from TEP, DEAP and MEAP to CCl4. Analysis of the relative energies along the potential energy surfaces has indicated energetically favoured attack on the chlorine atom of CCl4 relative to that on the carbon atom and the reactions became energetically more facile due to introduction of the electron donating diethylamino substituent. This allowed formulating the heterolytic mechanism of the reactions in which the quick exchange of CCl3- with the chlorine atom takes place for TEP, while the exchange is sloweddown in DEAP and MEAP due to mesomeric stabilization of the phosphonium ion. The ELF and Atoms in molecules (AIM) studies indicated early transition states (TSs) with no new covalent bond formation, and the non-covalent interactions at the interatomic bonding regions of the TSs are analysed from the Independent Gradient Model (IGM) analysis based on the Hirshfield partition of electron density. Page(s): 127-135 2022-02-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/59195 Title: Synthesis and characterization of Ni(II) and Cu(II) complexes based on quercetin Schiff base and using them as heterogeneous catalysts in Henry reaction Authors: Moodi, Zahra; Bagherzade, Ghodsieh Abstract: Quercetin is a dietary flavonoid, which with its specialized structure can form Schiff bases and their metal complexes. Schiff base ligand has been synthesized through the condensation of quercetin and ethanolamine. In this paper, two new metal complexes involving the Schiff base ligand have been prepared by a simple method at room temperature. SBL-Cu and SBL-Ni have been characterized by elemental analysis, ICP, UV-visible, and FT-IR studies. The activity of the synthesized complexes as a heterogeneous catalyst has been assessed in Henry reaction. The complexes have shown high catalytic performance in Henry reaction. However, SBL-Cu had better catalytic activity than SBL-Ni. These catalysts can be recycled and reused five times without a significant reduction in the activity. A series of benzaldehyde derivatives have been applied in the optimized Henry reaction to investigate the effect of the substituent group on the yield of the reaction. As expected, benzaldehydes containing electron-withdrawing group have a higher yield in Henry reaction. Page(s): 136-143 2022-02-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/59194 Title: Solvation studies of dimethylsulfoxide in non-aqueous solvents at high temperatures and at an atmospheric pressure Authors: Kaur, Manpreet Abstract: Solvation studies of pure non aqueous liquids like dimethylsulfoxide, pyridine and nitromethane and their binary mixtures have been measured at 0, 20, 40, 60, 80 and 100 mol% of pyridine and nitromethane at 298 K, 308 K and 318 K temperatures. Density, viscosity and ultrasonic velocities of the solvents have been measured. From the measured data, the isentropic compressibility and acoustic parameters like acoustic impedance, free volume, intermolecular free length, internal pressure, Gibb’s free energy, relaxation time, Rao’s constant, absorption coefficient, Wada’s constant, and entropy are calculated using experimental velocities, viscosities and densities at three different temperatures (298 K, 308 K and 318 K) and 1 atm pressure. Page(s): 144-153 2022-02-01T00:00:00Z