• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.797-800
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• 2002

Instead of a solution process producing amorphous $LiV_3O_8$ form, we prepared Lithium vanadate glass by melting $Li_2O-P_2O_5-V_2O_5$ and $Li_2O-P_2O_5-Bi_2O_3-V_2O_5$ composition in pt. crucible and by quenching on the copper plate. From the crystallization of $Li_2O-P_2O_5-V_2O_5$ and $Li_2O-P_2O_5-Bi_2O_3-V_2O_5$, we could abtain glass-ceramics having crystal phase, LiV3O8 from glass matrix. The material heat-treated at lower-temperature, $250^{\circ}C$ had less crystalline and lower capacity, But the material heat-treadted at higher-temperature, $330^{\circ}C$ had higher capacity and $Li_2O-P_2O_5-V_2O_5$ glass-ceramics had higher capacity than $Li_2O-P_2O_5-Bi_2O_3-V_2O_5$ glass-ceramics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.157-159
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• 2000

Vanadate glass in the $Li_2O-P_2O_5-V_2O_5$ system with 60mol% $V_2O_5$ was prepared by melting the bath in pt. crucible followed by quenching on the copper plate. We found that $Li_2O-P_2O_5-V_2O_5$ glass ceramics obtained from nucleation of $Li_2O-P_2O_5-V_2O_5$ glass showed significantly higher capacity and longer cycle life than conventionally made crystalline $LiV_3O_8$. In the present paper, We describe the charge/discharge properties during crystallization process and find the best crystallization condition of $Li_2O-P_2O_5-V_2O_5$ glass as cathode material. The Charge and discharge capacity of $Li_2O-P_2O_5-V_2O_5$ glass was about 220mAh/g for the cell heat-treated at $250^{\circ}C$ for 2.5hr.

• Journal of the Korean Magnetics Society
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• v.2 no.3
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• pp.222-227
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• 1992

The effects of $V_2O_5$ addition as an additive on the densification, the microstructure and the magnetic properties of Mn-Zn ferrites were studied. The maximum density was observed at 0.1 wt% $V_2O_5$ content and it was recognized that a small content of $V_2O_5$ prohibited the discontinuous grain growth. The initial permeability showed maximum at 0.1 wt% $V_2O_5$ content and the power loss minimum at 0.03 wt% $V_2O_5$ content. It was found that a small content of $V_2O_5$ went into solid solution in the Mn-Zn ferrites, but above that extent $V_2O_5$ formed a second phase to be segregated at the grain boundaries.

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.313-318
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• 2013

In order to investigate the effect of $V_2O_5$ loading of $V_2O_5-WO_3/TiO_2$ catalyst on the NO reduction and the formation of $N_2O$, the experimental study was carried out in a differential reactor using the powder catalyst. The NO reduction and the ammonia oxidation were, respectively, investigated over the catalysts compose of $V_2O_5$ content (1~8 wt%) based on the fixed composition of $WO_3$ (9 wt%) on $TiO_2$ powder. $V_2O_5-WO_3/TiO_2$ catalysts had the NO reduction activity even under the temperature of $200^{\circ}C$. However, the lowest temperature for NO reduction activity more than 99.9% to treat NO concentration of 700 ppm appeared at 340 with very limited temperature window in the case of 1 wt% $V_2O_5$ catalyst. And the temperature shifted to lower one as well as the temperature window was widen as the $V_2O_5$ content of the catalyst increased, and finally reached at the activation temperature ranged $220{\sim}340^{\circ}C$ in the case of 6 wt% $V_2O_5$ catalyst. The catalyst of 8 wt% $V_2O_5$ content presented lower activity than that of 8 wt% $V_2O_5$ content over the full temperature range. NO reduction activity decreased as the $V_2O_5$ content of the catalyst increased above $340^{\circ}C$. The active site for NO reduction over $V_2O_5-WO_3/TiO_2$ catalysts was mainly related with $V_2O_5$ particles sustained as the bare surface with relevant size which should be not so large to stimulate $N_2O$ formation at high temperature over $320^{\circ}C$ according to the ammonia oxidation. Currently, $V_2O_5-WO_3/TiO_2$ catalysts were operated in the temperature ranged $350{\sim}450^{\circ}C$ to treat NOx in the effluent gas of industrial plants. However, in order to save the energy and to reduce the secondary pollutant $N_2O$ in the high temperature process, the using of $V_2O_5-WO_3/TiO_2$ catalyst of content $V_2O_5$ was recommended as the low temperature catalyst which was suitable for low temperature operation ranged $250{\sim}320^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.523-527
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• 2000

Vanadate glasses in the Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ system containing 10mo1% glass former, P$_2$O$_{5}$ were prepared by melting the batch in pt. crucib1e followed by quenching on the copper plate. We found that Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass-ceramics obtained from nucleation of glass showed significantly higher capacity and longer cycle life than conventionally made crystalline LiCoO$_2$, LiNiO$_2$and LiV$_3$O$_{8}$. In the present paper, We describe electro-chemical properties during crystallization process and find the best crystallization condition of Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ g1ass as cathod material. Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass-ceramics shows superior rechargeable capacity of 220 mAh/g in the cycling between 2.0 and 3.9V.etween 2.0 and 3.9V.

• Applied Chemistry for Engineering
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• v.2 no.4
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• pp.330-339
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• 1991

The acid properties of $V_2O_5-TiO_2/SiO_2$ catalysts and the partial oxidation of o-xylene into phthalic anhydride had been investigated in order to relate the acid property of catalyst to the catalytic activity. $V_2O_5$ had both weak (V=O) and strong (V-O-V) acid sites which gave pyridine desorption peaks at $230^{\circ}C$ and $300^{\circ}C$, respectively, and the amount of weak acid sites at $230^{\circ}C$ decreased with the increase of calcination temperature. On the other hand, the amount of weak acid sites increased considerably by increasing the amount of $TiO_2$ to the $V_2O_5-TiO_2/SiO_5$, and the maximum value was shown at 20 and higher mole % of $TiO_2$ with respect to $SiO_2$. In the oxidation of o-xylene, $V_2O_5-TiO_2/SiO_2$ enhandced more the total conversion and the selectivity to phthalic anhydride than $V_2O_5/SiO_2$, and the higher $TiO_2$ ratio to $V_2O_5$ increased the total conversion but could not change the selectivity to phthalic anhydride. Weak acid sites (V=O) led o-xylene to partial oxidation producing phthalic anhydride by adsorbing o-xylene weakly, while acid sites (V-O-V) led it to total oxidation producing CO and $CO_2$ by adsorbing it strongly.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2459-2465
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• 2007

V2O5/TiO2-ZrO2 catalyst modified with V2O5 was prepared by adding Ti(OH)4-Zr(OH)4 powder into an aqueous solution of ammonium metavanadate followed by drying and calcining at high temperatures. The characterization of prepared catalysts was performed using XRD, DSC, solid-state 51V NMR, and FTIR. In the case of calcination temperature of 500 oC, for the catalysts containing low loading V2O5 below 25 wt % vanadium oxide was in a highly dispersed state, while for catalysts containing high loading V2O5 equal to or above 25 wt % vanadium oxide was well crystallized due to the V2O5 loading exceeding the formation of monolayer on the surface of TiO2-ZrO2. The strong acid sites were formed through the bonding between dispersed V2O5 and TiO2-ZrO2. The larger the dispersed V2O5 amount, the higher both the acidity and catalytic activities for acid catalysis.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.4
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• pp.451-463
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• 2004

The performance of disk-type catalytic filters impregnated by TiO$_2$ or TiO$_2$-3Al$_2$O$_3$ㆍ 2SiO$_2$ supports and V$_2$O$_{5}$ catalyst was evaluated for selective catalytic reduction (SCR) of NO with ammonia as a reductant. XRD, FT -IR, BET and SEM were used to characterize the catalytic filters prepared in this work. Optimal V$_2$O$_{5}$ loading and reaction temperature for V$_2$O$_{5}$/TiO$_2$ catalytic filters were 3-6 wt.% and 350-40$0^{\circ}C$ at GHSV 14,300 $hr^{-1}$ in the presence of oxygen, respectively. With increasing the V$_2$O$_{5}$ loading from 0.5 to 6 wt%, NO conversion increased from 24 to 96% at 40$0^{\circ}C$ and 14.300$hr^{-1}$, and maintained at 80% over in the V$_2$O$_{5}$ loading range of 3-6 wt.% and then dropped at V$_2$O$_{5}$ loading of 7wt.% over. In comparing V$_2$O$_{5}$/ TiO$_2$ and V$_2$O$_{5}$/ TiO$_2$-3Al$_2$O$_3$ㆍ2SiO$_2$ catalytic fillers, which have same 3wt.% V$_2$O$_{5}$ loading, the V$_2$O$_{5}$/ TiO$_2$-3A1$_2$O$_3$ㆍ2SiO$_2$ catalytic filter showed higher activity than V$_2$O$_{5}$/ TiO$_2$ catalytic filter, but higher differential pressure drops owing to its low air permeability. low air permeability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.550-553
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• 2001

$Li_{2}O-P_{2}O_{5}-Bi_{2}O_{3}-V_{2}O_{5}$ glass containing glass former, $P_{2}O_{5}$ and $Bi_{2}O_{3}$ was prepard by melting the glass batch in pt. erucible followed by guenching on the copper plate. We found that $Li_{2}O-P_{2}O_{5}-Bi_{2}O_{3}-V_{2}O_{5}$ glass-ceramics obtained from the crystallization of glass showed signifieantly higher capacity and longer cycle life tham $LiV_{3}O_{8}$ made from powder synthesis. In this paper, we described crystallization process and $LiV_{3}O_{8}$ crystal growth in glass matrix by increasing temperature. The electrochemical properties were strongly affected by $LiV_{3}O_{8}$ crystal growth in matrix

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.550-553
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• 2001

Li$_2$O-P$_2$O$_{5}$-Bi$_2$O$_3$-V$_2$O$_{5}$ glass containing glass former, P$_2$O$_{5}$ and Bi$_2$O$_3$ was prepard by melting the glass batch in pt. erucible followed by quenching on the copper plate. We found that Li$_2$O-P$_2$O$_{5}$-Bi$_2$O$_3$-V$_2$O$_{5}$ g1ass-ceramics obtained from the crystallization of glass showed significantly higher capacity and longer cycle life tham LiV$_3$O$_{8}$ made from powder synthesis. In this paper, we described crystallization process and LiV$_3$O$_{8}$ crystal growth in glass matrix by increasing temperature. The electrochemical properties were strongly affected by LiV$_3$O$_{8}$ crystal growth in matrix.rowth in matrix.