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difference of MnO x -based catalysts. In this study, protonated titanate is employed as a novel support for Mn species and MnO x /titanate is tested as a possible catalyst for the NH 3 -SCR reaction. The improved activity of MnO x /titanate compared to MnO x

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Introduction Protonated titanate nanotubes synthesized by the hydrothermal method have become the target of many studies in recent years because of its unique combination of physicochemical and structural properties [ 1

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] H.-J. Feng , F.-M. Liu , Materials Science (cond-mat.mtrl-sci), Apr 23 2007, http://arxiv.org/pdf/0704.2695, 7 pages. Influence of Barium Titanate over V-LDEC Separation 58 Journal of Planar Chromatography 29 ( 2016

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, ZJ 2001 Sol-gel synthesis of free-standing ferroelectric lead zirconate titanate nanoparticles . J Am Chem Soc 123 : 4344 – 4345 10.1021/ja001893y . 9. Ren , ZH , Xu , G , Liu , Y

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Abstract  

Because of unique dielectric, piezoelectric, thermoelectric, optical and ferroelectric properties of titanates of alkaline earth metals, they have become an object of many scientific research. This article is concerned with mechanochemical synthesis of calcium titanate as an alternative technique to hydrothermal, sol–gel, thermal methods. The aim of this study was to verify the mechanochemical conditions of CaTiO3 formation with the use of three calcium oxide precursors—CaO, CaCO3 and Ca(OH)2. The differences in processes of calcium titanate synthesis are presented.

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In this article, mechanochemical synthesis of barium titanate from different raw materials was studied. The prepared nanodispersed powders were investigated by means of XRD, DTA-TG, DSC, FTIR, Raman, UV–VIS, ESR spectroscopy, and low-temperature adsorption of nitrogen. Barium titanate possessing high specific surface area was produced directly during dry milling from the mixtures of barium oxides and titanium dioxide low-temperature forms (amorphous and anatase).

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Embedding of barium titanate into porous oxide matrices via sol–gel synthesis and introduction in structured slurry based on fumed oxides has been carried out. Prepared compositions have been studied using XRD, DTA-TG, FTIR, TEM, and adsorption of nitrogen. It has been established that simultaneous formation both barium titanate crystal structure and porous structure of matrices occurs. Crystallites of barium titanate, which arise in pores, possess lesser size in comparison with that for bulk BaTiO3.

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Preliminary examinations regarding formation of bismuth titanates in a part of Bi2O3—TiO2 system rich with TiO2 have been carried out. Bismuth titanates have been synthesized from mixtures of Bi2O3 and TiO2 (anatase) by the conventional solid-state method at the temperatures ranged from 1273 to 1473 K. Differential thermal analysis (DTA), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) have been used to study the formation of bismuth titanates. The following compounds have been achieved: Bi4Ti3O12, Bi2Ti2O7 and Bi2Ti4O11. Existence of controversial bismuth titanate of formula Bi2Ti3O9 in the Bi2O3—TiO2 system has not been confirmed.

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Abstract  

A series of rare-earth-doped sodium titanates with the chemical formula RxHyNa4 − (x+y)TiO4·nH2O (where R = Ce3+, Nd3+ and Sm3+) were grown employing solid-state fusion reaction technique. The physico-chemical investigations indicated that the new materials were self engineered into large particles enough to be used in sorption process and having crystalline structures containing localized Na+ ions. Equilibrium studies revealed that an enhancement in sorption efficiency of sodium titanate after rare-earth doping. The neodymium-rich sodium titanate exhibited a better exchange affinity for Cs+ compared to the other studied series. Data on the kinetics of cesium exchange fit well to pseudo-second order and intra-particle diffusion models. In a separate experiment, it was reported that the R-HNaTi series showed responsible sorption affinity toward Ce, Nd and Sm ions in their solution mixture with insignificant selectivity trend which reflects the high stability of titanate matrices.

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Abstract  

A new form of semicrystalline sodium titanate was synthesized at high temperature (1100-1150 °C) by a reaction of TiO2 with Na2CO3 in an equimolar ratio. The obtained product was characterized using IR, DTA-TG, X-ray diffraction and elemental analyses. According to X-ray patterns, H2Ti5O11 . nH2O with monoclinic structure has been formed on dehydration of semicrystalline sodium titanate. Kinetic studies of the order and activation energy of a new phase transformation have been determined from DTA-thermograms. The ion exchange behavior of semicrystalline sodium titanate was studied at different g-doses as well as at different drying temperatures. The laboratory-scale ion exchange capacity, distribution studies and exchange performance for some radionuclides of a thermally prepared material were investigated. It was found that the exchange capacity was not changed after 100 kGy irradiation.

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