Niobium oxide promoted by alkali metal nitrates for soot particulate combustion: Elucidating the vital role of active surface nitrate groups

With the target to develop efficient base metal oxide catalysts for soot particulate combustion, Nb2O5 promoted by different alkali metal nitrates has been prepared as catalysts with an impregnation method....

CO2 Hydrogenation to Synthetic Natural Gas over Ni, Fe and Co–Based CeO2–Cr2O3

CO2 methanation was studied over monometallic catalyst, i.e., Ni, Fe and Co; on CeO2-Cr2O3 support. The catalysts were prepared using one-pot hydrolysis of mixed metal nitrates and ammonium carbonate. Physicochemical properties of the pre- and post-exposure catalysts were characterized by X-Ray Powder Diffraction (XRD), Hydrogen Temperature Programmed Reduction (H2-TPR), and Field Emission Scanning Electron Microscope (FE-SEM). The screening of three dopants over CeO2-Cr2O3 for CO2 methanation was conducted in a milli-packed bed reactor. Ni-based catalyst was proven to be the most effective catalyst among all. Thus, a group of NiO/CeO2-Cr2O3 catalysts with Ni loading was investigated further. 40 % NiO/CeO2-Cr2O3 exhibited the highest CO2 conversion of 97.67% and CH4 selectivity of 100% at 290 °C. The catalytic stability of NiO/CeO2-Cr2O3 was tested towards the CO2 methanation reaction over 50 h of time-on-stream experiment, showing a good stability in term of catalytic activity.

Crystal structures with infinite chains based on antimony tartrate dimers

Seven complex metal antimony tartrates have been synthesized in single crystal form by slowly evaporating aqueous solutions of potassium antimony tartrate (tartar emetic) and divalent metal nitrates or perchlorates. Crystal structures of these compounds all contain infinite chains formed by linking antimony tartrate dimers with divalent metal ions. While infinite chains of antimony tartrate dimers bridged by single Zn2+ ions or by double Mg2+ ions were reported previously, new types of chains with alternating single and double bridging cations are observed in this work.

Extractive crystallization of salts in the ternary systems sodium (potassium, cesium) nitrate – water – triethylamine

A comparative analysis of the results of our polythermal study of the ternary systems sodium (potassium, cesium) nitrate – water – triethylamine has been carried out to estimate the efficiency of the use of triethylamine in the extractive crystallization of alkali metal nitrates from water–salt solutions containing 43.0, 44.0, 45.0, 46.0, and 47.0 wt. % sodium nitrate in the range of 10.0–25.0°C, 20.0, 21.0, and 22.0 wt.% potassium nitrate and 18.0, 19.0, 20.0 and 21.0 wt. % cesium nitrate in the range of 20.0–25.0°C. The dependences of the yield of these salts on the amount of triethylamine added and temperature have been found. It has been established that the maximum yield of sodium nitrate (79.4%) is observed for the aqueous solution with 47 wt.% salt upon the introduction of 90 wt.% triethylamine at 25.0° C. The maximum yield in the systems potassium (cesium) nitrate – water – triethylamine was 68.9% (22 wt. % potassium nitrate solution) and 66.2% (21 wt. % cesium nitrate solution) at 20.0° C and 90 wt. % amine content.

Third phase formation behaviour of tris(2-methylbutyl) phosphate and tri-n-alkyl phosphates in the extraction of mineral acids and tetravalent metal ions

The formation of third phase is a detrimental phenomenon witnessed in the nuclear separation processes during the extraction of certain metal salts by an organic solution, which comprises of a neutral extractant, tri-n-butyl phosphate dispersed in a non-polar diluent, n-dodecane (n-C12H26). In the present work, a comparative analysis on the third phase formation behaviour of three trialkyl phosphates, TBP, its linear and branched higher homologues tri-n-amyl phosphate and tris(2-methylbutyl) phosphate (T2MBP), respectively, have been provided which will be useful for the identification of an extractant with minimum third phase formation tendency. The organic phase splitting behaviour during the extraction of three mineral acids (HClO4, HCl and HNO3) and two tetravalent metal nitrates (Th(IV) and Zr(IV)) by trialkyl phosphates has been investigated to understand the influence of anionic and cationic components, respectively, in third phase formation of trialkyl phosphates. The effect of structure of the alkyl groups of trialkyl phosphate and chain length of diluents on third phase formation during Zr(IV) extraction from HNO3 media have also been studied. Overall, the third phase formation behaviour of T2MBP was found to be lower both for the extraction of mineral acid and Zr(IV), thereby indicating its potentiality for applications in various solvent extraction processes.

PREPARATION OF Cu MATRIX COMPOSITE REINFORCED WITH IN-SITU NANOSIZED Al2O3 PARTICLE POWDER FROM METAL NITRATES

The objective of the present work is to investigate the feasibility of the synthesis of copper matrix composite reinforced with in-situ nanosized Al2O3 particle powder via combustion synthesis method from metal nitrates followed by reducing process at high temperature. The starting nitrates Cu(NO3)2.3H2O and Al(NO3)3·9H2O composition corresponds to Cu-30%Al2O3. X-ray Diffraction (XRD) patterns of the obtained powders indicated the presence of the oxides CuO and CuAl2O4. The powder had the size of 75 ± 10 nm after deagglomerating by soft ball milling for 24h. After reducing in CO at 1000oC for 3h, the peaks of the oxides were no longer observed and were replaced by the peaks of Cu and -Al2O3. The morphology of the reduced powders observed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis showed well distribution of the -Al2O3 particles within the Cu matrix with an average particle size of 40 nm.

Synthesis, characterization of Novel β-diketone Ni, Fe, Cr Complexes and study of its Antifungal, Antibacterial, Antioxidant and Anti-Inflammatory Activity.

Theβ-dike toneis synthesizedvia the named Baker-Venkataraman. In currenttask, β-dike tone ligand mixed with different metal nitrates and form different metal complexes such as Ni(II), Fe(III), Cr(III). Ligand gives tautomerism, this tautomerism process was examined with the help ofFTIR.Because of enol assist as ligand in the metal complexes preparation. The preparedmetal complexearede scribed by various techniques like elemental analysis, FTIR, DTA, TGA, magnetic properties and molar conductivities. Different properties of complexes are studied such as antioxidant, antibacterial, anti-inflammatory and anti fungal properties.