• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.666-672
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• 2011

The catalytic activity of an inorganic-organic complex with a vanadium-substituted polyoxometalate 1, formulated as [Cu(2,2'-bipy)]$[Cu(2,2'-bipy)_2]_2[PMo_8V_6O_{42}]{\cdot}1.5H_2O$ was studied in the Biginelli reactions. The obtained results showed that, in the one-pot synthesis of dihydropyrimidinones, the turnover frequencies (TOF) for the [Cu(2,2'-bipy)]$[Cu(2,2'-bipy)_2]_2[PMo_8V_6O_{42}]{\cdot}1.5H_2O$ catalyst were higher than the $H_3PMo_{12}O_{40}$ catalyst.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.552-556
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• 2000

The crystallization behavior and dc Conductivities of CuO-Nb$_2$O$_{5}$ -V$_2$O$_{5}$ glasses prepared by quenching on the copper plate were investigated. The conductivities of the glasses were range from 10$^{-4}$ s.$cm^{-1}$ / at room temperature, but the conductivities of the glass-ceramics were 10$^{-3}$ s.$cm^{-1}$ / increased by 10$^1$ order. The linear relationship between In($\sigma$T) and T$^{-1}$ suggested that the electrical conduction in the present glass system would be due to a small polaron hopping mechanism. The value of activation energy of glass-ceramics heat-treated at 30$0^{\circ}C$ for 12hrs was found to be 0.leV

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.125.1-125
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• 2000

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1110-1114
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• 1998

The crystallization behaviors and electrical conductivities of the glasses heat-treated at various times and temperatures in the CuO-Bi$_2$O$_3$-V$_2$O$_{5}$ glass system were investigated. Among glass samples with various compositions, the highest conductivity obtained in the 31CuO-14Bi$_2$O$_3$-55V$_2$O$_{5}$ (mol%) glass sample. The 31CuO-14Bi$_2$O$_3$-55V$_2$O$_{5}$ (mol%) glass sample crystallized by heat treatment at 358$^{\circ}C$ for 8h had 2.67$\times$10$^{-2}$ $\Omega$$^{-1}$ $cm^{-1}$ /, which was much high value as a solid electrolyte. Compared to the glass sample, the heat- treated glass sample was increased in conductivity by an order of 10$^3$-10$^4$due to the formation and growth of BiVO$_4$ and CuVO$_3$crystals.

• Journal of the Korean Magnetics Society
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• v.8 no.2
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• pp.62-66
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• 1998

We have studied on the magnetic properties of the specimen with additives Bi$_2$O$_3$and$V_2O_5$ that sintered at 900 $^{\circ}C$ for 4 hours for sybthesizing optimal Ni-Zn-Cu ferrite. Curie temperature rises from 240 $^{\circ}C$ to 270 $^{\circ}C$ as Ni contents increase. Magentic maximum induction$(B_m)$ increases from 2650 G to 3300 G, 3500 G in the specimens with $V_2O_5$ and Bi$_2$O$_3$resectively. On the contrary coercive force $(H_c)$ lowers to 2.05 Oe~1.05 Oe. Permeability all increase in the specimen with additives. In the specimen with additive Bi$_2$O$_3$, we have obtained the low relative loss factor of $6.3{\times}10^{-5}~7.84{\times}10^{-5}$ in the range of 1MHz due to increase of resistivity in grain boundary. In the specimen with additive $V_2O_5$ in spite of increase permeability relative loss factor increase of due to decrease of Q-value.

• Resources Recycling
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• v.22 no.4
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• pp.38-45
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• 2013

The porous ceramic beads using mine tailing were prepared and applied to catalytic converter for NOx/SOx removal. Catalytic support was used synthesized mesoporous silica (SBA-15) which coated on surface. Internal structure for porous ceramic beads was composed of three-dimensional network structure and porosity was about 80%. In addition, the specific surface area for mesoporous silica(SBA-15) coated on converter was significantly increased 55 $m^2/g$ compared with 0.8 $m^2/g$ before coating. NOx/SOx removal experiment was performed using $V_2O_5$ and $V_2O_5$/CuO converter. NOx conversion ratio for $V_2O_5$/CuO converter was approximately increased 10% compared to $V_2O_5$ converter. In addition, catalytic converter of $V_2O_5$/CuO was shown to remove 95% of NOx and 90% of SOx at reaction temperature of $350^{\circ}C$, space velocity of 10000 $h^{-1}$ and $O_2$ concentrations of 5%, respectively.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.327-336
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• 1994

The synergistic effects in mechanical mixture catalysts of Mo-V-O and metal oxide were investigated for the selective oxidation of acrolein. The metal oxides used are $SnO_2$, ${\alpha}-Sb_2O_4$, $WO_3$, ${\alpha}-Al_2O_3$, CuO, $MnO_2$, $Cu_2O$, MgO, CoO, and ZnO. Mechanical mixtures of Mo-V-O plus $SnO_2$ or ${\alpha}-Sb_2O_4$ had resulted in higher conversion of acrolein and higher yield of acrylic acid than Mo-V-O. The origin of the synergy is attributed to the cooperation of Mo-V-O and $SnO_2$ or ${\alpha}-Sb_2O_4$, in which $SnO_2$ or ${\alpha}-Sb_2O_4$ forms dissociated oxygens at their oxygen vacancies and transports them to Mo-V-O. $Cu_2O$, MgO, CuO, and $MnO_2$, increased conversion of acrolein but decreased yield of acrylic acid. CoO and ZnO inhibited the catalytic performance of Mo-V-O. The different role of these metal oxides is explained in terms of their oxidation-reduction properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.842-844
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• 2004

Ternary tellurite glassy systems $(CuO-V_2O_5-TeO_2)$ have been synthesised using tellurium oxide as a network former and copper oxide as network modifier. The addition of a transition-matal oxide makes them electric or mixed electric-ionic conductors, which are of potential interest as cathode materials for solid-state batteries. This glass-ceramics crystallized from the $CuO-V_2O_5-TeO_2$ system are particularly interesting, because they exhibit high conductivity ( up to $6.03{\times}10^{-3}S/cm$) at room temperature. the glass samples were prepared by quenching the melt on the copper plate and the glass-ceramics were heat-treated at crystallizing temperature determined from differential thermal analysis (DTA). The electric D.C conductivity result have been analyzed in terms of a small polaron-hopping model.

• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.916-922
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• 1997

A superconducting phase La2CuO4+δ (Tc=44 K) has been prepared by electrochemical oxidation which allows the oxygen to intercalat into the La2O2 layers. According to the Cu K-edge X-ray absorption near edge structure spectroscopic analysis, the oxidized phase shows an overall spectra shift of about 0.5 eV to a higher energy region compared to the as sintered one with the occurrence of an additional peak corresponding to the transition to the |1s13dn+1L-14pσ1 > final state, indicating the oxidation of CuO2 layer. From the X-ray photoelectron spectroscopic studies, it is found that the binding energy of La 3d5/2 is significantly shifted from 834.3 eV (as sintered La2CuO4) to 833.6 eV (as electrochemically oxidized La2CuO4+δ), implying that the covalency of the (La-O) bond is decreased due to the oxygen intercalation. The O 1s spectra do not provide an evidence of the superoxide or peroxide, but the oxide (O2-) with the contaminated carbonate (CO32-) based on the peaks at 529 eV and 532 eV, respectively, which is clearly confirmed by the Auger spectroscopic analysis. Oxygen contents determined by iodometric titration (δ=0.07) and thermogravimetry (δ=0.09) show good coincidence each other, also giving an evidence for the "O2-" nature of excess oxygen. From the above results, it is concluded that "O2-" appeared as O 1s peak at 528.6 eV is responsible for superconductivity of La2CuO4+δ.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.609-617
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• 2000

This study is aimed at investigating an effect of HCl gas on selective reduction of NOx over a CuHM and $V_2O_5-WO_3/TiO_2$ catalyst. SCR process is the most effective method to remove NOx, but catalyst can be deactivated by the acidic gas such as HCl gas which is also included in flue gas from the incinerator. In dry condition of flue gas, the CuHM catalyst treated by HCl gas has shown higher NO removal activity than the fresh catalyst. The activity of the catalyst can be restored by treating at $500^{\circ}C$. On the contrary. $V_2O_5-WO_3/TiO_2$ catalyst is obviously deactivated by HCl and the deactivation increases in proportion to the concentration of HCl gas. The deactivated catalyst is not restored to it's original activity by heat treatment for regeneration. In wet flue gas stream, the CuHM catalyst has shown lower activity than fresh catalyst and $V_2O_5-WO_3/TiO_2$ catalyst was severely deactivated by HCl treatment. The activity loss of catalysts are mainly due to the decrease of Br$\ddot{o}$nsted acid site on the catalyst surface by $NH_3$ TPD. The change of BET surface area of CuHM catalyst after the reaction isn't observed but $V_2O_5-WO_3/TiO_2$ catalyst is observed. The amount of $Cu^{{+}{+}}$ and $V_2O_5$ is decreased after the reaction. From these results, it is expected that CuHM catalyst should be better than $V_2O_5-WO_3/TiO_2$ catalyst for its application to the incineration of flue gas.