• Rubber Technology
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• v.13 no.1
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• pp.1-9
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• 2012

Click chemistry had enjoyed a wealthy decade after it was introduced by K.B.Sharpless and his co-worker on 2001. Since there is no optimized method for synthesis of click polymer, therefore, this paper introduced three click reaction methods such as catalyst, non-catalyst and azide-end capping for fluorene-based functional click polymers. The obtained polymers have reasonable molecular weight with narrow PDI. The polymers are thermally stable and almost emitted blue light emission. The synthesized fluorene-based functional click polymers were characterized to compare the effect of click reaction methods on polymer electro-optical properties as well as device performance on quasi-solid-state dye sensitized solar cells (DSSCs) applications. The DSSCs with configuration of $SnO_2:F/TiO_2/N719$ dye/quasi-solid-state electrolyte/Pt devices were fabricated using these click polymers as a solid-state electrolyte components. Among the devices, the catalyzed click polymer composed device exhibited a high power conversion efficiency of 4.62% under AM 1.5G illumination ($100mW/cm^2$).These click polymers are promising materials in device application and $Cu^I$-catalyst 1, 3-dipolar cycloaddition click reaction is an efficient synthetic methodology.

• Journal of the Korean Electrochemical Society
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• v.16 no.1
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• pp.52-58
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• 2013

In order to overcome the cost issue for commercialization of polymer electrolyte membrane fuel cell (PEMFC), this research was conducted for replacing platinum cathode catalyst with non-precious metal catalyst. The non-precious metal catalyst (Co-PANI-C) was synthesized by the simple reduction method with polyaniline (PANI), carbon black, and cobalt precursor without any heat treatment. Characterization of new Co-PANI-C composite catalysts was done by the measurement of X-ray diffraction (XRD) and thermogravimetric analysis (TGA) for structure analysis and performed by rotating disk electrode (RDE) and rotating ring disk electrode (RRDE) for electrochemical analysis. As a result, Co-PANI-C catalyst showed 60 mV lower on-set potential for oxygen reduction reaction (ORR) than Pt/C catalyst, but the overall reduction current of Co-PANI-C catalysts by ORR was still smaller than that of Pt/C. In addition, the ORR behavior of Co-PANI-C catalysts depending on the rotation speed of electrode and the stability of Co-PANI-C catalyst under potential cycling and the performance of fuel cell conditions are also discussed.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.157-162
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• 2014

In this research, we investigate electrical performance and electrochemical properties of carbon supported Pt (Pt/C) that is synthesized by polyol method. With the Polyol_Pt/C that is adopted for oxygen reduction reaction (ORR) as cathode of proton exchange membrane fuel cells (PEMFCs), their catalytic activity and ORR performance and electrical performance are estimated and compared with commercial Pt/C(Johnson Mattey) catalyst. Their electrochemically active surface (EAS) area are measured by cyclic voltammetry (CV), respectively. On the other hand, regarding ORR activity and electrical performance of the catalysts, (i) linear sweeping voltammetry by rotating disk electrode and (ii) PEMFC single cell tests are used. The CV measurement demonstrate EAS of Polyol_Pt/C is compared with commercial JM_Pt/C. In case of Polyol_Pt/C, its half-wave potential, kinetic current density are excellent. Based on data obtained by half-cell test, when PEMFC single cell tests are carried out, current density measured at 0.6V and maximum power density of the PEMFC single cell employing Polyol_Pt/C are better than those employing commercial Pt/C. Conclusively, Polyol_Pt/C synthesized by modified polyol process shows better ORR catalytic activity and PEMFC performance than other catalysts.

• Journal of Sensor Science and Technology
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• v.5 no.1
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• pp.23-29
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• 1996

Thick film type gas sensors with parallel Pt heaters were fabricated by screen printing process and investigated sensitivities for methane gas. The TR7905 was selected as Pt paste for heater by characterization the properties of TCRs and thick film microstructures. The average resistance of parallel Pt heaters was $1.8{\Omega}$, and the best TCR obtained was $3685\;ppm/^{\circ}C$. On the top of the Pt heaters, a sensing layer added with Pt and Pd as catalyst paste was screen printed and heat treated. The sensitivity of the sensor was 4.3mV/1000ppm for methane. The power consumption of the sensors was 2.12watts.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.129-135
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• 2016

CO oxidation was performed with Cu-Mn and Cu-Zn co-precipitated catalysts as differential precipitant, metal ratio and calcination temperature. The effects of differential metal mole ratio and calcination temperature in mixed metal oxide catalyst were investigated with CO oxidation reaction. Physiochemical properties were studied by XRD, $N_2$ sorption and SEM. 2Cu-1Mn with $Na_2CO_3$ catalyst calcined at $270^{\circ}C$ has a large surface area $43m^2/g$ and the best activity for CO oxidation. $Cu_{0.5}Mn_{2.5}O_4$ in XRD peak shows the lower activity than others. The catalytic activity over the catalyst calcined $270^{\circ}C$ displayed the highest conversion, and it was better activity comparing with Pt catalysts CO conversion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3261-3266
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• 2012

Sodium borohydride($NaBH_4$) known as the material of hydrogen generation and storage can produce the hydrogen via catalytic hydrolysis. This protide chemical could be used in the hydrogen supply system for residential and mobile fuel cells, and thus many researches and developments regarding to these chemicals and decomposition reactions have been implemented. We experimented the hydrolysis of $NaBH_4$ alkaline solution by metal oxide-supported PGM(platinum group metal) catalysts and measured the generation rate of hydrogen which is product of decomposition reaction. We compared oxides as catalyst supports, and the precious metals, Pt and Ru for the catalysts and studied the effects of amounts of catalyst added and $NaBH_4$ concentrations on the hydrogen generation rates and patterns.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.3
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• pp.199-208
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• 2008

HI decomposition was conducted using Pt/C-based catalysts with a fixed-bed reactor in the range of 573 K to 773 K. To examine the change of the characteristic properties of the catalysts, $N_2$ adsorption analyser, a X-ray diffractometer(XRD), and a scanning electron microscopy(SEM) were used before and after the HI decomposition reaction. the effect of Pt loading on HI decomposition was investigated by $CO_2$-TPD. HI conversion of all catalysts increased as decomposition temperature increased. The XRD analysis showed that the sizes of platinum particle became larger and agglomerated into a lump during the reaction. From $CO_2$-TPD, it can be concluded that the cause for the increase in catalytic activity may be attributed to the basic sites of catalyst surface. The results of both b desorption and gasification reaction showed the restriction on the use of Pt/C-based catalyst.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.685-691
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• 1992

The $d^8$-transition metal complexes containing diphosphine, $MCl_2PP$ were prepared by using $K_nMCl_m$ as starting materials, wherein M were Ni(II), Pd(II), Pt(II) and Au(III) and PP were bis(diphenylphosphino)methane(dppm), bis(diphenylphosphino)ethane(dppe), bis(diphenylphosphino)propane (dppp) and bis(diphenylphosphino)ethylene(dppety). The complexes were characterized by the spectral property $(^H-NMR$, $^{31}P-NMR$ and UV-Visible spectra) together with elemental analysis. The complexes were tested for the catalytic activity on the formation reactions of 3(2H)-furanone and cyclic carbonate. The only Ni(II)- and Pd(II)-diphosphine complexes displayed a good catalytic effects in the production of 3(2H)-furanone from 2-methyl-3-butyn-2-ol [reaction (1)]. But all the diphosphine complexes as catalyst were almost inactive towards cyclic carbonate production preaction [reaction (2)].

• Journal of Sensor Science and Technology
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• v.3 no.3
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• pp.9-15
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• 1994

Catalytic combustible gas sensors were fabricated by using ${\gamma}-Al_{2}O_{3}$ with large surface area and noble metal catalysts. The optimum conditions for ${\gamma}-Al_{2}O_{3}$ fabrication were investigated by DT/TGA and XRD analyses and it was found that fabricated ${\gamma}-Al_{2}O_{3}$ had superior value as surface area of $215.5m^{2}/g$. Gas sensors were manufactured and tested to inflammable gases by using Pt coil as a heater and temperature sensing part, fine ${\gamma}-Al_{2}O_{3}$ powder as a bead material and Pt, Pd noble metal powder as a catalyst. From the results, fabricated sensor showed good sensitivity to LPG and LNG of 20mV/l000ppm, 6.5mV/l000ppm respectively.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.4
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• pp.310-315
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• 2012

A simple drying process was developed for the preparation of a Pt/Nafion self-humidifying membrane to be used for a proton-exchange membrane fuel cell (PEMFC). Platinum (II) bis (acetylacetonate), $Pt(acac)_2$ was sublimed, penetrated into the surface of a Nafion film and then reduced to Pt nanoparticles simultaneously without any support of a reducing agent in a glass reactor at $180^{\circ}C$ for 15 min. The process was carried out in $N_2$ atmosphere to prevent the oxidation of Pt nanoparticles at high temperature. The morphology and distribution of the Pt nanoparticles were observed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS), and we found that the average Pt particle size was ca. 3.7 nm, the penetration depth was ca. $17{\mu}m$. Almost all Pt nanoparticles were formed just beneath the surface and the number density decreased rapidly as the penetration depth increased. To estimate water absorption characteristics of the Nafion membranes, water uptake at an isothermal condition was measured by dynamic vapor sorption (DVS), and it was found that water uptake of the Pt/Nafion membrane was higher than that of the neat Nafion membrane.