7558-02-3Relevant articles and documents
Enhanced liquid phase catalytic hydrogenation reduction of bromate over Pd-on-Au bimetallic catalysts
Zhou, Juan,Zhou, Xin,Li, Liyuan,Chen, Quanyuan
, p. 142 - 149 (2018)
Pd-Au/TiO2 bimetallic catalysts with varied Au contents were prepared by the sequential photocatalytic deposition method and the liquid phase catalytic hydrogenation reduction of bromate over these catalysts was investigated. The catalysts were characterized using X-ray diffraction, transmission electron microscope, UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, H2 chemisorption and energy dispersive spectroscopy. Characterization results showed that Pd atoms were site-deposited on the surface of varied size Au cores and formed Pd-on-Au core-shell like bimetallic nanoparticles on TiO2. The bimetallic catalysts showed higher Pd dispersions and more exposed active sites than that of Pd/TiO2, and the amount of exposed active sites first increased then decreased with Au content. For a similar Pd loading, the bimetallic catalyst exhibited volcano-shape activity as a function of Au loading and the highest activity was identified on Pd-Au(1.0)/TiO2 with Au core size around 8.4 nm. In addition, the catalytic reduction of bromate could be well-fitted by the Langmuir-Hinshelwood model, reflecting an adsorption controlled mechanism.
Synthesis and characterization of K8-x(H2) ySi46
Neiner, Doinita,Okamoto, Norihiko L.,Yu, Ping,Leonard, Sharon,Condron, Cathie L.,Toney, Michael F.,Ramasse, Quentin M.,Browning, Nigel D.,Kauzlarich, Susan M.
, p. 815 - 822 (2010)
A hydrogen-containing inorganic clathrate with the nominal composition, K7(H2)3Si46, has been prepared in 98% yield by the reaction of K4Si4 with NH4Br. Rietveld refinement of the powder X-ray diffraction data is consistent with the clathrate type I structure. Elemental analysis and 1H MAS NMR confirmed the presence of hydrogen in this material. Type I clathrate structure is built up from a Si framework with two types of cages where the guest species, in this case K and H2, can reside: a large cage composed of 24 Si, in which the guest resides in the-6d position, and a smaller one composed of 20 Si, in which the guest occupies the 2a position (cubic space group Pm3 n). Potassium occupancy was examined using spherical aberration (Cs) corrected scanning transmission electron microscopy (STEM). The highangle annular dark-field (HAADF) STEM experimental and simulated images indicated that the K is deficient in both the 2a and the 6dsites. 1H and 29Si MAS NMR are consistent with the presence of H2 in a restricted environment and the clathrate I structure, respectively. FTIR and 29Si{1H} CP MAS NMR results show no evidence for a Si-H bond, suggesting that hydrogen is present as H2 in interstitial sites. Thermal gravimetry (TG) mass spectrometry (MS) provide additional confirmation of H2 with hydrogen loss at ～400 °C.
Complex antimony(III) oxohalides: Synthesis and physicochemical properties
Panasenko,Zemnukhova,Kavun,Merkulov
, p. 163 - 168 (2012)
Complexes of the formula MSb2BrF4O (M = K, Rb, and NH4) were obtained from aqueous solutions of SbF3 and MBr and examined by chemical analysis, X-ray diffraction, thermal analysis, and IR, Raman, and 19F NMR spectroscopy. It was found that the red reflectance is 74-97% and the UV reflectance is 7-15%. The highest averaged reflectance (93%) was observed for KSb2BrF4O. The decomposition temperatures of MSb2BrF4O (M = K, Rb, and NH4) are 230, 197, and 223°C, respectively. Pleiades Publishing, Ltd., 2012.
Synthesis and thermolysis of tris(triethoxysiloxy)aluminum and its complexes with potassium and sodium triethoxysilanolates
Shcherbakov,Basova,Khorshev,Malysheva,Domrachev
, p. 394 - 397 (2002)
Reaction of potassium (or sodium) triethoxysilanolate with AlBr 3 in benzene in a 3:1 or 4:1 ratio yields, respectively, tris(triethoxysiloxy)aluminum Al[OSi(OEt)3]3 or potassium (or sodium) tetrakis(triethoxysiloxy)alumin
A novel zero valent metal bismuth for bromate removal: Direct and ultraviolet enhanced reduction
Huang, Hong,Liu, Guoshuai,Wang, Xiuheng
, p. 4148 - 4155 (2020/02/04)
Bromate (BrO3-) is a carcinogenic and genotoxic by-product of the ozone disinfection process. In this study, a new zero-valent metal, bismuth, was used to reduce bromate. Bismuth samples were prepared by a solvothermal method and characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The morphology of the bismuth powder was microspheres assembled with dense nanosheets. The kinetics of the direct bromate reduction by bismuth accorded with the pseudo-first-order kinetics model. The rate coefficients of the initial bromate concentration of 1.00 mg L-1, 2.50 mg L-1, 5.00 mg L-1 were identically close to 0.08 min-1. For 0.20 mg L-1, a reaction rate coefficient near 0.10 min-1 was obtained. The reducing products of bromate included bromide ions (Br-) and bismuth oxybromides. The bromate removal efficiency was enhanced remarkably in the presence of ultraviolet (UV) light, and the corresponding kinetic coefficient was 4 times higher than that of direct reduction. The mechanism of ultraviolet enhancement was analyzed by diffuse reflectance spectroscopy (DRS), the density functional theory (DFT) calculation, open circuit potential (OCP) analysis, photocurrent measurement and linear sweep voltammetry (LSV). Besides, the influence of dissolved oxygen (DO) on bromate reduction efficiency and the sustainability of the as-prepared sample were investigated. DO inhibited the reduction rate obviously, but showed a slight effect on the formation of bromide ions. In the long-term periodic experiments, the kinetic coefficient decay occurred in both direct (without UV irradiation) and ultraviolet assisted bromate reduction. However, the kinetic coefficient of UV-assisted reduction (0.115 min-1) was about 2 times higher than that of the direct reduction in the last cycle of periodic experiments. In conclusion, the novel bromate reduction strategy based on the zero-valent bismuth metal material has been proved efficient and sustainable, which contributes to the development of drinking water treatment technologies.
Synthesis, characterization, and catalytic behavior of methoxy- and dimethoxy-substituted pyridinium-type ionic liquids
Manikandan, Chitrarasu,Ganesan, Kilivelu
, p. 3362 - 3367 (2014/12/11)
Synthesis of methoxy-substituted pyridinium-type ionic liquids from a nontoxic and easy method is described. Catalytic behaviors of synthesized ionic liquids were investigated with various concentrations for the Mannich reaction. We have observed that methoxy- and dimethoxy-substituted pyridinium bromides showed better catalytic behavior than other ionic liquids.
