Advanced Materials Research Vols. 750-752

Abstract: With sulfur-contained oil tanks undergoing chemical corrosions, the corresponding products (i.e. rust, mainly comprising of Fe₂O₃, Fe₃O₄ and Fe (OH)₃) would react with hydrogen sulfide, sulfur, mercaptan sulfur and other active sulfur contained in the oil to produce highly oxidizing iron sulfide, which is liable to cause fire and explosions upon exothermic reactions. In this paper, the corrosion induced by low-temperature wet H₂S and natural oxidations of corresponding products within the sulfur-contained oil tanks are simulated. An analysis is also made on the temperature changing patterns during the sulfidation of Fe₂O₃, Fe₃O₄, Fe (OH) ₃, and their mixtures as well as in the natural oxidation process of sulfide. Research results indicate that due to the strong oxidation tendency revealed by ferrous sulfide generated from reactions between Fe₂O₃, Fe₃O₄, Fe (OH) ₃, and their mixtures with wet H₂S under anaerobic conditions, it can react with oxygen in the natural air violently to release a lot of heat. The higher the content of Fe₂O₃ and Fe₃O₄, the greater the risk of spontaneous combustion would be. Moreover, the oxidation of iron sulfide undergoes three phases in natural environment, i.e. oxidation induction, oxidation incubation, and oxidation acceleration.

Abstract: The coordination polymer, [Sm₂(HPyImDC)₂Ox (H₂O)₂·6H_2n [H₃PyImDC = 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid, Ox = oxalate], has been synthesized under hydrothermal conditions and characterized by elemental analysis, FT-IR and single crystal X-ray diffraction. It crystallizes in monoclinic, space group C2/c with a = 28.166(6), b = 6.9970(14), c = 16.655(3) Å, V = 2685.4(9) ų, Z = 4, D_c = 2.298 g/cm³, μ(MoKα) = 4.428 mm^-1, F(000) = 1852, the final R = 0.0412 and wR = 0.1010. The complex forms a three-dimensional (3D) framework structure.

Abstract: 4-phenylethynylphthalic anhydride (4-PEPA) was synthesized by the palladium/copper catalyzed Sonogashira coupling reaction between phenylacetylene and 4-bromophthalic anhydride. The yield achieved 85.48%. The single crystal of 4-PEPA was grown and crystallized by solvent diffusion method. The structure of the compound was characterized by single crystal X-ray diffract-tion method, UV-vis, ¹H NMR, ¹³C NMR and FTIR. All characterizations above demonstrated the structure of 4-PEPA. HPLC gave the purity achieving 96.62%. TGDSC was used to investigate the thermal stability of the compound. Vibrational frequencies of 4-PEPA calculated using the density functional theory (DFT/B3LYP) method with the 6-31G(d) basis sets were in good agreement with experimental values.

Abstract: Cu/SiO₂ catalyst by using Na₂SiO₃ as the silicon source, and the catalytic activity for 2-butanol dehydrogenation was compared with the conventional traditional industrial catalysts (Cu/Al and Cu/Zn). The catalysts were characterized by FTIR and XRD. The copper hydrosilicate was detected as the main phase in the dried sample. Cu₂O was detected in reduced sample, and can effectively prevent Cu⁰ to forming big size particle. The Cu/SiO₂ catalyst compared with Cu/Al and Cu/Zn presented a much higher activity and stability in 2-butanol dehydrogenation process.

Abstract: Cu-ZnO catalysts prepared by coprecipitation and physical mixing methods were characterized to investigate the roles of ZnO by X-ray diffraction (XRD), N₂O chemisorption decomposition and evaluated for the vapor-phase dehydrogenation of sec-butanol (SBA) to methyl ethyl ketone (MEK). ZnO not only could disperse Cu species, but also prevent Cu⁰ from sintering. Cu-ZnO catalyst by coprecipitation method exhibited excellent reactivity.

Abstract: First principles calculations are performed to investigate the structural and elastic properties of SbI₃ based on density functional theory for two space groups: trigonal R-3 and monoclinic P2₁/c. The calculated equilibrium structural parameters agree well with the experimental data. The enthalpy calculations confirm that the trigonal R-3 structure of SbI₃ is the most stable structure at zero pressure. For R-3 structure, the obtained bulk, shear, and Youngs modulus are 28.1, 15.2 and 38.6 GPa, respectively. The calculated Debye temperature is 197 K. SbI₃ presents large elastic anisotropy, stronger compressibility and better ductility at 0 GPa.

Abstract: A new dual-bed photocatalytic hydrogen production reaction system is proposed in this paper. In this dual-bed system, one bed is photocatalytic hydrogen evolution reaction bed in which I^- is oxidized into I₂ by a hole and H⁺ is reduced to H₂ by an electron, and the other is the hole-sacrificed agent regeneration bed in which I^- is regenerated by reducing I₂ with Cu₂O. The two reaction beds are connected with two constant flow pumps to form a circulation loop. The hole-sacrificed agent I^- can always be renewable by circulating the reaction solution between dual beds. The dual-bed reaction system achieves to produce hydrogen continuously, steadily and efficiently.

Abstract: Li₄Ti_5-xAl_xO₁₂ (x=0.03, 0.05, 0.10) were prepared by a solution method. The electrochemical performances including charge-discharge and AC impedance were investigated. The structure of the samples were characterized by X-ray diffraction. The results revealed that proper Al doped into Li₄Ti₅O₁₂ would not change or destroy the crystal structure. Li₄Ti_5-xAl_xO₁₂(x=0.03, 0.05) had better capacity than Li₄Ti₅O₁₂, because of the decrease of electric resistance. But when the quality percent of Al was too big, it will bring negative influence to Li₄Ti₅O₁₂. Al³⁺ doping did not change the electrochemical process, instead enhanced the electronic conductivity and ionic conductivity. The reversible capacity and cycling performance were effectively improved.

Abstract: Four new multinuclear cobaltadithiolene complex derivatives [Cp*CoFe₂(CO)₆(η², μ₃-S₂C₆H₂(SC₃H₇)₂)] 1, [Fe (CpPPh₂)₂(Cp*CoS₂C₆H₂(SC₃H₇)₂)₂] 2, [Cp*CoRu (CO)₃(CH₂=CHCH₂) (η²,μ₂-S₂C₆H₂(SC₃H₇)₂)] 3 and [Cp*Co (NSO₂C₆H₄CH₃)(S₂C₆H₂(SC₃H₇)₂)] 4 were obtained by reaction of mono-nuclear cobaltadithiolene complex [Cp*CoS₂C₆H₂(SC₃H₇)₂] (Cp*=C₅(CH₃)₅) with Fe₃(CO)₁₂, Fe (CpPPh₂)₂ (1,1'-bis (diphenylphosphino) ferrocene), Ru (CO)₃(CH₂=CHCH₂)Br, C₆H₅I= NSO₂C₆H₄CH_3(p) (N-(Phenyliodonio)-p-toluene sulfonamidate), respectively. All new complexes were characterized by C/H analysis, ¹H NMR, MS and IR spectroscopy. Furthermore, the optical and electrochemical properties of some complexes were also determined by UV-Vis spectra and cyclic voltammogram (CV) analysis.

Abstract: In this paper, Mg (HCO₃)₂ solution, was obtained by the carbonate reaction of Mg (OH)₂ solution , using magnesite as raw materials. Mg ion concentration was measured by ICP-AES method. The effect of carbonization temperature, carbonization time, flux of CO₂ and agitation speed on the concentration of Mg ion in Mg (HCO₃)₂ solution was investigated. Results showed that Mg ion concentration reduced with increasing temperature, but increased a little as time went on and flux of CO₂ improved. With increasing the agitation speed, Mg ion concentration increased firstly, then decreased, finally remained unchanged. XRD analysis shows that the purity of obtained Mg (HCO₃)₂ solution is very high.