N. Deb

Bio: N. Deb is an academic researcher from North Eastern Regional Institute of Science and Technology. The author has contributed to research in topics: Thermal decomposition & Oxalate. The author has an hindex of 11, co-authored 24 publications receiving 273 citations. Previous affiliations of N. Deb include Dibrugarh University.

Thermal decomposition behaviour of lanthanum(III) tris-tartrato lanthanate(III) decahydrate

Abstract: Lanthanum(III) tris-tartrato lanthanate(III) decahydrate, La[La(C4H4O6)3]·10H2O has been synthesized and characterized by elemental analysis, IR, electronic spectral and X-ray powder diffraction studies. Thermal studies (TG, DTG and DTA) in air showed a complex decomposition pattern with the generation of an anhydrous species at ~170°C. The end product was found to be mainly a mixture of La2O3 and carbides at ~970°C through the formation of several intermediates at different temperature. The residual product in DSC study in nitrogen at 670°C is assumed to be a similar mixture generated at 500°C in TG in air. Kinetic parameters, such as, E*, ΔH, ΔS, etc. obtained from DSC are discussed. IR and X-ray powder diffraction studies identified some of the decomposition products. The tentative mechanism for the thermal decomposition in air of the compound is proposed.

Thermal Investigations of M[La(C2O4)3]⋅xH2O (M=Cr(III) and Co(III))

Abstract: The complexes M[La(C2O4)3]⋅xH2O (x=10 for M=Cr(III) and x=7 forM=Co(III)) have been synthesized and their thermal stability was investigated. The complexes were characterized by elemental analysis, IR, reflectance and powder X-ray diffraction (XRD) studies. Thermal investigations using TG, DTG and DTA techniques in air of chromium(III)tris(oxalato)lanthanum(III)decahydrate, Cr[La(C2O4)3]⋅10H2O showed the complex decomposition pattern in air. The compound released all the ten molecules of water within ∼170C, followed by decomposition to a mixture of oxides and carbides of chromium and lanthanum, i.e. CrO2, Cr2O3, Cr3O4, Cr3C2, La2O3, La2C3, LaCO, LaCrOx (2

Some heterobimetallic oxalate coordination precursors of lanthanum(III) of the type, M3[La(C2O4)3(H2O)m]2·nH2O (M = Mn(II), Co(II), Ni(II) and Cu(II))

Abstract: Heterobimetallic oxalato complex precursors, manganese(II)tetraaquatris(oxalato)lanthanate(III)hexahydrate (MnOLa), cobalt(II)pentaaquatris(oxalato)lanthanate(III)trihydrate (CoOLa), nickel(II)pentaaquatris(oxalato)lanthanate(III)hexahydrate (NiOLa) and copper(II)diaaquatris(oxalato)lanthanate(III)monohydrate (CuOLa) of the type, M3[La(C2O4)3(H2O) m ]2·nH2O have been synthesized in aqueous medium. The precursors were characterized by elemental analysis, IR, electronic spectral and powder X-ray diffraction studies. The good crystalline nature with monoclinic structures predominates in MnOLa and NiOLa whereas triclinic structures were found in CoOLa and CuOLa. The solid-state thermal behaviour of the precursors was explored using TG, DTG and DTA in air. The MnOLa generated a mixture species consisting mainly of MnO2, Mn3O4, Mn5O8, La2O3 and LaMn7O12 at 1000 °C through the formation of several intermediate species at 380 and 570 °C. The studies revealed that CoOLa led mainly to LaCoO3 and La2CoO4 along with some oxides of both the cobalt and lanthanum at 1000 °C. In case of nickel analogue the mixture species identified at 1000 °C are mainly of La2NiO4, La2O3, Ni2O3 and NiO2. In case of CuOLa the product at 1000 °C consisted of La2CuO4, La2Cu2O5 and oxides of copper and lanthanum. The nature of decomposition of the precursors in nitrogen were seen from DSC study and the kinetic parameters i.e., E * , lnk 0, ΔH # , ΔS # and order of reaction of all the steps were evaluated and discussed.

Copper-supported pillared clay catalysts for the wet hydrogen peroxide catalytic oxidation of model pollutant tyrosol

Abstract: The catalytic wet hydrogen peroxide oxidation of tyrosol, a major compound of the polyphenolic fraction present in olive oil mill wastewaters, was studied in batch and continuous reactors using copper-supported pillared clay catalysts under mild conditions. The catalysts were prepared by the solid-state reaction of Al-pillared clay synthesized with copper nitrate. The resultant materials were then calcined at 300 °C for 3 h under helium or oxygen. The catalytic activity of Cu-supported pillared clays was found to depend on the calcination method. The effects of several operating conditions were also studied. Our experimental results indicate that, under mild conditions and a stoichiometric amount of oxidant, the calcined material under helium (CuNHe catalyst) showed higher activity and stability (TOC abatement of roughly 80% and total elimination of tyrosol after 1 h reaction, without significant leaching of copper ions) than the calcined material under oxygen (CuNOxy). To better understand the catalytic behaviour of copper-supported pillared clay solids, fresh and used catalysts were characterized by X-ray diffraction, nitrogen adsorption, chemical analysis, temperature-programmed reduction (TPR), UV–visible diffuse reflectance spectroscopy, and transmission electron microscopy (TEM).

Thermal analysis study of some transition metal complexes by TG and DSC methods

Abstract: The thermodynamic and thermal properties of [Cu(L)2·Cl2], [Ni(L)2]·Cl2, [Co(L)2·Cl2]; L=1,2-bis(o-aminophenoxy)ethane (BAFE), complexes have been investigated. The thermal decomposition of the complexes took place in two distinct steps in endothermic reaction up to 700°C. The activation energy E, the entropy change S #, enthalpy H change and Gibbs free energy change G # were calculated from the results of thermogravimetry analysis (TG) and heat capacity from the results of differential scanning calorimetry (DSC). It was found that the thermal stabilities and activation energies of the complexes follow the order Ni(II)>Cu(II)>Co(II) and E Co