• 한국광물학회지
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• 제9권2호
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• pp.93-101
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• 1996

Behavior of platinum group elements during crystallization within ore magma is of interest. In this study platinum is selected and its mineralogical and geochemical behavior in the presence of antimony and tellurium is investigated at 600$^{\circ}C$. High purity Pt, Sb, and Te are used as starting material and silica quartz tubings are as container. Rection products have been examined by use of ore microscope, X-ray diffractometer, electron microprobe analyser and micro-indentation hardness tester. stable phases at 600$^{\circ}C$ are platinum (Pt), Pt5Sb, Pt3Sb, PtSb, stumpflite (PtSb), geversite (PtSb), PtTe, Pt3Te4, Pt2Te3, moncheite (PtTe2), tellurantimony (Sb2Te3), and antimony (Sb). Geversite is the mineral showing the most significant extent of solid solution by up to 27 at% between Sb and Te elements. Isothermal section of 600$^{\circ}C$ is established in this study. It is noted that platinum cannot coexists with stumpflite or geversite under equilibrium condition, and stumpflite composition in equilibrium with geversite may be used as geothermometer.

• 한국재료학회지
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• 제26권1호
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• pp.17-21
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• 2016

Pt@Cu/C core-shell catalysts were successfully prepared by impregnation of a carbon support with copper precursor, followed by transmetallation between platinum and copper. The Pt@Cu/C core-shell catalysts retained a core of copper with a platinum surface. The prepared catalysts were used for hydrogen production through catalytic dehydrogenation of decalin for eventual application to an onboard hydrogen supply system. Pt@Cu/C core-shell catalysts were more efficient at producing hydrogen via decalin dehydrogenation than Pt/C catalysts containing the same amount of platinum. Supported core-shell catalysts utilized platinum highly efficiently, and accordingly, are lower-cost than existing platinum catalysts. The combination of impregnation and transmetallation is a promising approach for preparation of Pt@Cu/C core-shell catalysts.

• 한국재료학회지
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• 제25권4호
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• pp.191-195
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• 2015

To improve its textural properties as a support for platinum catalyst, carbon aerogel was chemically activated with KOH as a chemical agent. Carbon-supported platinum catalyst was subsequently prepared using the prepared carbon supports(carbon aerogel(CA), activated carbon aerogel(ACA), and commercial activated carbon(AC)) by an incipient wetness impregnation. The prepared carbon-supported platinum catalysts were applied to decalin dehydrogenation for hydrogen production. Both initial hydrogen evolution rate and total hydrogen evolution amount were increased in the order of Pt/CA < Pt/AC < Pt/ACA. This means that the chemical activation process served to improve the catalytic activity of carbon-supported platinum catalyst in this reaction. The high surface area and the well-developed mesoporous structure of activated carbon aerogel obtained from the activation process facilitated the high dispersion of platinum in the Pt/ACA catalyst. Therefore, it is concluded that the enhanced catalytic activity of Pt/ACA catalyst in decalin dehydrogenation was due to the high platinum surface area that originated from the high dispersion of platinum.

• Bulletin of the Korean Chemical Society
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• 제6권4호
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• pp.214-217
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• 1985

Platinum(II) complexes of R-2,2'-diaminobinaphthyl (R-dabn), [Pt(R-dabn)(H2O)2]Cl2, [Pt(R-dabn)(R-Pn)]Cl2, [Pt(R-dabn)(R-bn)]Cl2, and platinum(II) complexes of S-2,2'-diaminobinaphthyl (S-dabn), [Pt(S-dabn)(H2O)2]Cl2, [Pt(S-dabn)(S-Pn)]Cl2, and [(Pt(S-dabn)(S-bn)]Cl2 have been prepared. (R-Pn and S-Pn are, respectively R- and S isomer of 2,3-diaminobutane). R-Pn and S-bn are, respectively R and S isomer of 2,3-diaminopropane). In the vicinity of the B-absorption band region of dabn, the circular dichroism spectra of platinum(Ⅱ) complexes of R-dabn series show a positive B-band followed by a negative higher energy A-band, which is generally understood as the splitting pattern for a ${\lambda}$ conformation, while the circular dichroism spectra of platinum(Ⅱ) complexes of S-dabn series show a negative B-band followed by a positive higher energy A-band in the long-axis polarized absorption region as expected for a $\delta$ conformation.

• Advances in nano research
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• 제7권3호
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• pp.169-180
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• 2019

Plasmonic effects of gold and platinum alloy nanoparticles (Au-Pt NPs) and their comparison to size was studied. Various factors including ratios of gold and platinum salt, temperature, pH and time of addition of reducing agent were studied for their effect on particle size. The size of gold and platinum alloy nanoparticles increases with increasing concentration of Pt NPs. Temperature dependent synthesis of gold and platinum alloy nanoparticles shows decrease in size at higher temperature while at lower temperature agglomeration occurs. For pH dependent synthesis of Au-Pt nanoparticles, size was found to be increased by increase in pH from 4 to 10. Increasing the time of addition of reducing agent for synthesis of pure and gold-platinum alloy nanoparticles shows gradual increase in size as well as increase in heterogeneity of nanoparticles. The size and elemental analysis of Au-Pt nanoparticles were characterized by UV-Vis spectroscopy, XRD, SEM and EDX techniques.

• Bulletin of the Korean Chemical Society
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• 제19권7호
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• pp.733-737
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• 1998

Using an atom superposition and electron delocalization molecular orbital (ASED-MO) method, we have compared adsorption properties of adsorbates on the Pt(Ill) surface with the Pt(lll)/γ-Al203 surface in the ethylene hydrogenation reaction. In two-layer thick model systems, the calculated activation energy of the hydrogenation by the surface platinum hydride is equal to the energy by the hydride over supported platinum/γ-alumina. The transition structure on platinum is very close to the structure on the supported platinum/γ-alumina surface. Hydrogenation by the surface hydride on platinum can take place easily because the activation energy is about 0.5 eV less than hydrogenation by ethylidene. On supported platinum/,y-alumina the activation energy of the hydride mechanism is about 0.61 eV less than that of ethylidene mechanism. In one-layer thick model systems, the activation energy of hydrogenation by ethylidene is about 0.13 eV less than the activation energy of hydride reaction. The calculated activation energy by the hydride over the supported platinum y-alumina is 0. 24 eV higher than the platinum surface. We have found from this result that the catalytic properties of one-layer thick model systems have been influenced by the support but the two-layer thick model systems have not been influenced by the support.

• 대한화학회지
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• 제67권6호
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• pp.415-419
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• 2023

In this study, we report the one-pot synthesis of reduced graphene oxide (rGO) containing platinum nanoparticles with catalytic activity to break down hydrogen peroxide as a peroxidase-mimicking catalyst. A single reducing agent was used to reduce graphene oxide and a platinum precursor at a moderately low temperature of 70℃. The rGO was homogeneously decorated with platinum nanoparticles. The catalytic activity of Pt-rGO was investigated for the oxidation of 3,3',5,5'- tetramethylbenzidine (TMB), a peroxidase substrate, in the presence of hydrogen peroxide. The Pt-rGO coupled with glucose oxidase was also able to detect glucose at millimolar concentrations (up to 1 mM). Our results show that the Pt-rGO composite is a promising catalyst for the detection of hydrogen peroxide. This method was also applied for the detection of glucose.

• Bulletin of the Korean Chemical Society
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• 제17권5호
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• pp.457-460
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• 1996

The principal elements of the 31P NMR chemical shielding tensors have been determined for three binuclear platinum diphosphite complexes, K4[Pt2(P2O5H2)4·2H2O ("Pt2"), K4[Pt2(P2O5H2)4Cl2]·2H2O ("Pt2Cl2"), and K4[Pt2(P2O5H2)4Br2]·2H2O ("Pt2Br2"), by using a Herzfeld-Berger graphical method for interpreting the 31P MAS spectrum. The orientations of 31P chemical shielding tensor relative to the molecular axis system are partially assigned with combination of the longitudinal relaxation study of HPO32- and the reference to known tensor orientations of related sites; the most chemical shielding component, δ33, is directed along the P-Pt bond axis. A discussion is given in which the experimental principal elements of the 31P chemical shielding tensor are related with the Pt-Pt bond distances in binuclear platinum diphosphite complexes.

• 자원리싸이클링
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• 제16권5호
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• pp.36-40
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• 2007

백금은 물리화학적 특성에 기인하여 많은 분야에서 중요한 역할을 하고 있으며, 이러한 분야에서는 아주 미세한 백금의 사용을 요구하고 있다. 그러므로 본 연구에서는 액상에서 환원제를 사용하여 백금염을 환원시킴으로서 나노크기의 백금을 제조하는 방법에 대하여 알아보았다. 수용액상에서 C14TABr과 $H_2[PtCl_6]$ 상호작용은 $[C1_4TA]_2[PtCl_6]$의 유기백금염 화합물을 형성한다. 단분산 나노 백금입자를 얻기 위해서는 $C1_4TABr$과 $H_2[PtCl_6]$ 농도가 각각 cmc와 0.32 mM 이상이 되어야 한다. $H_2[PtCl_6]$와 C14TABr 농도가 증가함에 따라 백금입자 크기가 증가하였으며, 백금입자의 형태는 C14RABr농도 증가에 따라 제어가 가능하였다.

• 자원리싸이클링
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• 제26권3호
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• pp.79-91
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• 2017

수소연료전지자동차(FCV)의 핵심은 고분자고체형연료전지(Polymer Solid Fuell Cell: PEFC)이고 전지 중에서 전기화학적 전기를 발생하는 핵심 소재는 백금촉매이다. 백금은 남아프리카와 러시아 등에 편재되어있고, 백금의 세계생산량은 연간 약 178톤이고 고가이므로 리싸이클링 한다. 현재 PEFC에 Pt를 사용하는 양은 $0.2{\sim}0.1mg/cm^2$인데, 전지의 가격을 줄여서 FCV보급을 확대하기 위하여 사용하는 Pt양을 $0.05{\sim}0.03mg/cm^2$까지 감소시키는 것을 목표로 하여 각국이 연구 개발하고 있다. 나노배금 제조기술은 건식법과 습식법으로 크게 나누며 습식환원법을 중심으로 제조하는 방식이 Pt를 제조하는데 유리하다. 나노Pt를 이용하여 폴리올법, 개량형 Cu-UPD/Pt 치환법 및 나노캡슐법 등에 의해 $Pt-Pd/Al_2O_3$, Pt/C, Pt/GCB, Pt/Au/C, PtCo/C, PtPd/C 등의 Pt촉매가 연구 개발되고 있으며, Pt촉매의 활성향상 및 안정화 기술 등이 보고되고 있다. 본고는 나노Pt와 나노Pt촉매의 제조기술 및 폐 촉매의 리사이클링 및 Pt촉매의 응용기술 경향을 조사 분석하였다.