• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.229-232
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• 2005

The study on the improvement of manufacturing process of RJ-4 liquid fuel that have high flash point, was carried out. In preparing of RJ-4 using commercially available MCPD, 1st, 2nd hydrogenation and isomerization reaction were enabled 1 step continuous process by combined use of heteropoly phosphoroustungstic cesium salt catalyst and 2nd stage-heat-controllable reactor. Also when heteropolyacid cesium salt was used as a isomerization catalyst instead of aluminum chloride, formation rate of exe-THDMCPD was higher, the catalyst could be easily separable from product and there was no production of waste acid, so this new reaction condition was confirmed as the environment friendly process.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.431-437
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• 1994

The role and the formation of surface and bulk acid sites of heteropoly acids were studied by examining ethanol conversion and MTBE (methyl t-butyl ether) decomposition reaction. In ethanol dehydration diethylether was formed on the surface acid site of 12-tungstophosphoric acid, whereas ethylene was formed in the bulk acid site of the catalyst. It was revealed that water reinforced the bulk acid site of the catalyst, while organic base decreased the bulk acid function of the catalyst. The formation of acid sites of metal salts was due to hydrolysis of crystalline water and/or partial substitution of metal, and with hydrogen treatment, the acid site was reappeared. Also catalyst design as a selective oxidation catalyst was possible by controlling acid function of heteropoly acid catalyst.

• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.549-557
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• 1993

In the conversion of ethanol over heteropoly acids, we have studied catalytic reactivity, reaction mechanism, effect of organic bases added to reactant, and relation between acid strength of ion-exchanged catalysts and catalytic activities. The conversion of ethanol proceeded in the pseudoliquid phase of heteropoly acid. Due to this novel behavior, area increased by supporting with $SiO_2$. The reaction mechanism of ethylene production was different from that of ether production, and various partially substituted Al salts of 12-tungstophosphoric acid showed different catalytic activities.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.30-36
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• 1994

Reaction characteristics and correlations between the acidic property and catalytic activity of heteropoly acid catalyst on ETBE synthesis as a gasoline octane enhancer were investigated. The amount of pyridine adsorbed on heteropoly acid catalyst and catalytic activity in the synthesis of ETBE showed a good correlation. But ammonia failed to show such a correlation because of the complex formation of ammonia adsorbed and transition metal ions. In the case of supported catalyst catalytic activity and product distribution were mainly affected by the adsorption characteristics of TBA or iso-butene.

• Journal of the Korean Chemical Society
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• v.52 no.1
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• pp.23-29
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• 2008

Simple Keggin type tungsten and molybdenum heteropoly acids, H3PW12O40 and H3PMo12O40, were usedas water-tolerant catalysts for the oxidation of alcohols with 34% hydrogen peroxide in normal drinking water. Accordingto our findings, H3PW12O40 may be used as a simple, effective, and cheap catalyst for this type of transformation in nor-mal drinking water with excelent yields. Efects of diferent solvents at 25-80oC and changing concentration of catalystand substrate on the reaction progress were also studied.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.1
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• pp.77-84
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• 1995

To prevent or reduce air pollutant from methanol fueled vehicles, methanol oxidation reaction was carried out using a heteropoly acid catalysts. Catalytic activities of catalysts have been experimented at atmospheric pressure in a fixed bed flow reactor. Catalysts were characterized by XRD, IR, thermal analysis, N $H_{3}$-TPD and GC pulse technique. Acidities of catalysts were highly affected by poly-atoms. Methanol conversion was much higher on catalyst with W than on catalyst with Mo as a poly-atoms. With the increase of copper content(X) in C $u_{x}$ $H_{{3-2x}}$PMo catalyst, acidity was decreased and oxidation ability was increased. Methanol conversion and product distribution were affected by the acidity and oxidation ability of catalyst. Especially, supported PdSiW(1wt%) catalyst has a very good methanol conversion and C $O_{2}$ selectivity as high as a commertial 3-way catalyst.t.

• Journal of the Korean Chemical Society
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• v.20 no.1
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• pp.87-90
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• 1976

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1020-1027
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• 1999

Heteropoly acid(HPW) catalysts supported on three different carriers, an amorphous silica, MCM-41 and MCM-48, with different loadings and calcination temperatures have been prepared and characterized by X-ray diffraction, nitrogen physorption, infrared spectroscopy, and $^{31}P$ magic angle spinning NMR. From the result of IR and NMR, it was shown that HPW retains the Keggin structure on the supported catalysts. No HPW crystal phase was developed even at HPW loadings as high as 35 wt % on the MCM-41 and 65 wt % MCM-48. Thus, HPW appeared to form finely dispersed species. In the hydrolysis reaction of di, bis, tri-pentaerythritol, HPW/MCM-41, 48 exhibited higher catalytic activity than $HPW/SiO_2$ or HPW.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.162-170
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• 1993

Vapor-phase ETBE(ethyl tert-butyl ether) synthesis from TBA(tert-butyl alcohol) and ethanol was carried over solid acid catalysts such as heteropoly acids and proton type zeolites. Heteropoly acids were more active than proton type zeolites and $H_4SiW_{12}O_{40}$ catalyst showed about the same activity as Amberlyst-15 ion exchange resin catalyst used as an industrial catalyst in ETBE synthesis. The catalytic activity of transition metal exchanged heteropoly acids was greatly enhanced, because new acid site was generated with hydrogen reduction. This effect of hydrogen reduction was related to the reduction characteristics of catalysts and the order of reducibility was $Ag^+$>$Cu^{2+}$>$Fe^{2+}$.

• Applied Chemistry for Engineering
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• v.4 no.2
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• pp.335-341
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• 1993

In the conversion of methanol, the effect of acide property of heteropoly compounds on the catalytic activity was investigated. The pretreatment of Cu-exchanged 12-tungstophosphoric acid with hydrogen enhanced both the selectivity for propane and the conversion of methanol, and the pretreatment of Al-exchanged 12-tungstophosphoric acid with water enhanced the acid strength of the catalyst. The water added into the reactant decreased the conversion of methanol, while the pretreatment temperature did not affect it but the propylene/propane ratio. Various partially-substituted Al salts of 12-tungstophosphoric acid showed different catalytic activities depending on the degree of Al-substitution.