Advanced Materials Research Vols. 287-290

Abstract: Ce_0.7M_0.3CoO_x catalysts were prepared by polyatomic alcohol method. The crystal structure, reduction and adsorption properties, and specific surface were investigated by XRD, TPR, TPD, BET, respectively. The results show that catalysts doped with different oxides can make great effects on the catalytic properties of the Co₃O₄-CeO₂. The interaction between doping oxides (SrO, NiO, La₂O₃, ZrO₂, Nd₂O₃) and Co₃O₄-CeO₂ is contributed to the change of the reduction and adsorption performance, and specific surface area of the catalysts. SrO doping can promote CeO₂ reduction, CO adsorption and low-temperature oxidative activity of the catalysts. The conversion of CO can reach 100% over the Ce_0.7Sr_0.3CoO_x at 120 °C temperature.

Abstract: Water-based varnish is prone to generate a lot of bubbles when it is processed or used. The bubbles can cause coating defects during coating, so the film quality is not very well. Adding defoamer in varnish can quickly eliminate the bubbles. Changing the type and amount of the defoamer prepared varnish and tested its defoaming properties to discussion the influence of defoamer on defoaming properties of water-based varnish. The results show that the performance of different defoamers defoaming is different, and Foamex 810 has the best defoaming properties. The amount of adding defoamer impacts defoaming properties to a certain extent. When water-based varnish added Foamex 810 with the amount of 1% in, the defoaming efficiency comes to the peak 96%.

Abstract: Nanosized material tungstate zirconia (WO₃/ZrO₂) was prepared by surfactant -assisted precipitation. Structural characterizations of the catalyst were performed by N₂ adsorption– desorption and FTIR pyridine adsorption spectroscopy. Preparation of peracetic acid (PAA) from acetic acid (AA) and hydrogen peroxide (HP) under the catalysis of Lewis acid WO₃/ZrO₂ was investigated.

Abstract: Anatase nano-titania (nano-TiO₂) was prepared by using a sol-gel process mediated in reverse microemulsion combined with a solvent thermal technique. The results show that the anatase structure appears in the calcination temperature range of 400-510°C, while the transformation of anatase into rutile takes place above 510°C. The average particle size (d_P) of the nano-TiO₂ increases with the rise of water/Triton X-100 molar ratio (ω) but decreases with the rise of acetyl acetone/n-TBT molar ratio (p) and n-hexanol/Triton X-100 molar ratio (m). The obtained TiO₂ particles with a small size have high photocatalytic activity.

Abstract: The C, N, S tri-doped TiO₂ with high visible-light photo-catalysis effect was successfully prepared by mixing thiourea with the self-prepared TiO₂ powder through calcining for 2h at 450°C. The TiO₂ powder was obtained by homogeneous precipitation method using the metatitanic acid instead of expensive chemical reagents contained Ti as raw material. The effect of doping materials and methods on the photo-degradation rate of methylene blue and dyes was studied. The characterizations of the doped TiO₂ were analyzed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible absorption spectra (UV-vis). The results showed that this sample was the anatase TiO₂ and contained elements C, N, S. The sample exhibited a significant response to ultraviolet and visible light. In the photo-degradation experiment, the C, N, S, tridoped-TiO₂ could decolorize methylene blue and textile dyes quickly, and the photo-degradation rate of methylene blue could reach upward 98% after 3 hours under the different light sources.

Abstract: A CTAB-assisted microwave hydrothermal method was used to synthesize BiVO₄ photocatalysts with different shapes. The obtained products were characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV-vis diffuse reflectance spectroscopy (DRS). The results showed that the monoclinic phase BiVO₄ polyhedron was formed via a tetragonal zircon-type BiVO₄ precursor. UV-vis diffuse reflectance spectra showed a great shift to longer wavelengths in the visible region for the monoclinic phase BiVO₄ samples compared to the BiVO₄ precursor. The photocatalytic activity of the sample was investigated for the liquid phase photocatalytic degradation of RhB under visible light irradiation (λ>420nm). The effects of different reaction times on the photocatalytic activity of BiVO₄ had also been investigated, and the highest efficiency was observed when the sample was prepared at 140 °C for 30min.

Abstract: The catalytic transfer hydrogenolysis of 2-phenyl-2-propanol was studied over Pd/C catalyst, using formic acid and formate salts as hydrogen donors. The Pd/C catalyst was characterized by powder X-ray diffraction (XRD), inductively coupled plasma (ICP), N₂ adsorption/desorption and transmission electron microscopy (TEM). The effects of hydrogen donor, molar ratio of formic acid to 2-phenyl-2-propanol and water content were evaluated. Under mild reaction conditions (80 °C, 2h), 2-phenyl-2-propanol can be hydrogenolyzed to isopropylbenzene with very high selectivity (96.5%) and high conversion (92.8%) in the presence of Pd/C and formic acid. From the viewpoint of environmental friendly principles, this study may open the way to a new approach for the production of propylene oxide.

Abstract: The novel modified vermiculite adsorbents have been made impregnated with sulfate, HCl and CuCl₂. A laboratory-scale packed-bed reactor system was used to screen these adsorbents for their capability to remove elemental mercury. The affection of temperature on adsorption was also detected. Results showed that the adsorption capability for elemental mercury was improved after treated by different modified agents than the natural vermiculite. Comparing with active carbon, the adsorption capability of vermiculite adsorbents modified by sulfate and HCl were less improved, and it is almost increased 40 times than that of active carbon when using the CuCl₂ modified vermiculite adsorbent at the same condition. Increasing temperature is active for the adsorption capability for elemental mercury by sulfate and HCl modified vermiculite adsorbents.

Abstract: A catalyst of BTPD-Zn (BTPD= N,N’-Bis(2-thiophenecarboxaldehy) o-phenylenediamine) has been found to be active toward the copolymerization of cyclohexene oxide and carbon dioxide, and a kind of good biodegradable material named poly(cyclohexene carbonate) is prepared with turnover number of 105.8 in 100°C. The molar fraction (f_c) of polycarbonate in copolymer is 96%. The obtained copolymers were characterized by IR and NMR.

Abstract: The synthesizing CaZrO₃ are prepared with fused zirconia powder (0.044mm), monoatomic zirconia powder (0.044mm), desilication zirconia powder (0.044mm) and calcium oxide powder (0.044mm). The effect of different moulding pressure and firing temperature on synthesizing CaZrO₃ has been studied in this paper. The test results show that: The impurity composition SiO₂ and Al₂O₃ in raw material have participated in reaction, and generated liquid, accelerated transmission quality speed of reaction. Desilication ZrO₂ is the best ZrO₂ raw material to synthesizing CaZrO₃ in above three ZrO₂ raw materials, firing temperature markedly influence the synthetic rate of CaZrO₃, but moulding pressure is not this. Desilication ZrO₂ and CaO as raw material, firing 1600°C for 3h, pressure at 160Mpa and one stage burning process are the best technical conditions to synthesize CaZrO₃.