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Direct Transformation of Ethanol to Ethyl Acetate over MoSx/C Catalyst

Wang L. X., Zheng D. F., Ma C. X., Zhu W. C., Liu S. Y., Cui J., Wang Z. L., Zhang W. X.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 11

1993-2000

EN

Activated carbon-supported sulfided molybdenum catalysts were tested in transformation of ethanol to ethyl acetate. The catalytic activity of MoSx/C catalysts was found to depend strongly on preparation procedure. Surface atomic ratio of S/Mo on these catalysts was different and the catalyst with the ratio of S/Mo = 2.2 had better catalytic properties. For the purpose of enhancement of catalytic activity, the treatment of activated carbon support by HNO3 had been applied. Physicochemical characterization showed that the pretreatment was effective in obtaining a highly dispersed molybdenum species on the surface of the catalyst, which led to an in crease in conversion of ethanol.

2

Surface Structure and Catalytic Properties of Cu/SiO2 Catalysts Prepared by Different Methods

Ji D. H., Zou X. J., Zheng D. F., Wang L. X., Liu S. Y., Zhu W. C., Wang G. J., Wang Z. L.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 5

1097-1104

EN

The silica supported copper catalysts were prepared via impregnation (IM), solgel (SG) and deposition precipitation (DP) methods. The catalysts were characterized by XRD, H2-TPR, NH3-TPD, H2-N2O titration, XPS, BET and EPR techniques. The results indicated that two copper species, Cu2+ and Cu0 exist on the surface of SG catalyst; how ever, only Cu0 species could be found on the surface of reduced IM and DP catalysts, and the dispersion of Cu0 on IM catalyst was better than that on DP catalyst. According to the reaction results, Cu0 should be the active sites for dehydrogenation of cyclohexanol. Cu2+ species on the surface of SG catalyst might be responsible for the dehydration of cyclohexanol. The residual Na was found on the surface of DP catalyst, which made the acidity decreas ing, and the Cu crystallite growing up easily.

3

Effect of bending on transmission characteristics of polymeric arrayed waveguide grating multiplexers

Qin Z.K., Ma C.S., Li D.L., Li H., Zhang D.M., Liu S.Y.

Optica Applicata

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2008

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Vol. 38, nr 2

315-327

EN

In terms of the transmission theory of the arrayed waveguide grating (AWG), parameter optimization is performed, and bending effect of arrayed waveguides on transmission characteristics is analyzed for a 33×33 polymeric AWG multiplexer around the central wavelength of 1550.918 nm with the wavelength spacing of 0.8 nm. Analytical results show that the bending of arrayed waveguides causes the phaseshift of the light propagating in the AWG, results in the shift of the transmission spectrum, and brings about the variation of the crosstalk. For the designed AWG device, the Shift of the transmission spectrum is about 0.01 nm, which is much less than the wavelength spacing of 0.8 nm.

4

Design of athermal arrayed waveguide grating using silica/polymer hybrid materials.

Li D. L., Ma C. S., Qin Z. K., Zhang H. M., Zhang D. M., Liu S.Y.

Optica Applicata

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2007

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Vol. 37, nr 3

305-312

EN

This study demonstrates a novel athermal arrayed waveguide grating (AWG) which is composed of silica/polymer hybrid materials on a silicon substrate. The temperature-dependent wavelength shift of the AWG depends on the refractive indices of the materials and the size of the waveguide. The athermalization of the AWG can be realized by selecting the proper values of the material and structural parameters of the device.