Рrecipitation of platinum group metals (Rh, Ru, Pd, so-called MPG) from the melt essentially affects the reliability of installations for vitrification of high-level liquid radioactive waste (HLW). To date, it is difficult to find an approach which allows simultaneous recovery of all three metals. The aim of our work was to select a sorbent that would provide simultaneous up to complete recovery of given metals. The following inorganic materials were tested as sorbents – yellow blood salt (YBS).and hexacyanoferrates of iron, aluminum, copper and nickel. The degree of metal recovery was studied is influenced by the temperature and concentration of nitric acid. Only palladium was completely recovered using YBS. At the same time, specially prepared iron hexacyanoferrate (HCF-Fe) under optimal experimental conditions recovers almost all Pd and more than 95% and 90% of Rh and Ru, respectively. The behavior of fission products, including the main dose-forming components of HLW (Cs, Sr) and Mo, U, Ag, REE) in the course of MPG recovery was studied. The experiments were carried using both multicomponent model solutions and real raffinates. Options for further management of the recovered metals have been worked out. Thus, the proposed method of metal recovery seems promising for the development of a technology for the removal of MPG from nitric HLW during the reprocessing of the spent nuclear fuel (SNF) before vitrification. The recovered metals can be probably used in various technological processes. Also, this method can provide the MPG recovery from low-concentration tail solutions.

In the automotive industry, the platinum titanium anodes (Pt/Ti anode) play a significant role in electroplating of chromium coating on the vehicle’s shock absorber piston rod. In this paper, the structure of Pt/Ti anode was designed to obtain high quality and save time for the electroplating process. The structure of anode was designed in 2D & 3D modeling and analyzed by CATIA and ABAQUS program, respectively. The structural modeling of the anode was analyzed and carried out using a finite element method (FEM) by applied various loads. The manufacture anodes were installed in an electroplating bath in order to test the efficiency of chromium coating on shock absorber piston rod and safety of anode structure. The results presented indicate that the structural analysis is safe after applied loads due to the allowable stress is higher than the maximum equivalent stress about 4 times, and the chromium coating test obtained high-efficiency results.

본 연구에서는 하수슬러지 가용화를 위한 불용성전극을 개발하여 전기화학적 특성을 확인 하였다. 이리듐을 주촉매로 사용하여 하수슬러지 가용화에 적합한 촉매를 선정하여 내구성이 우수하고 하수슬러지 전기분해에 적합한 기능성 전극 실험을 진행하였고 다음과 같은 결과를 얻었다. 전극의 코팅 소성온도를 주 촉매인 Ir의 질량감소가 적고, 흡열반응 구간인 300℃부터 500℃까지의 범위로 선정하고 실험을 하였다. 실험결과 350℃에서 촉매의 효율성이 가장 우수하게 나왔다. 각각의 바인더 별(Ta, Sn, W) 실험에서도 350℃에서 가장 큰 촉매효율성이 나타났다. 바인더로 사용한 탄탈럼, 주석, 텅스텐 중 탄탈럼이 다른 금속보다 주 촉매의 특성을 그대로 유지시키며 전극의 효율성을 향상시키는 것을 확인하 였다. 50%IrO2 전극의 경우 1.4 V(vs. Ag/AgCl) 약 29 mA/cm2 의 전류가 발생하여 전극의 효율을 평 가하였다.

has the characteristic is controlling the inhibition or promotion of particle growth by adsorbing onto specific facets of platinum nanoparticles. Therefore, in this study, was added to control the shape of platinum nanoparticles during the liquid phase reduction process. Consequently, platinum cubes were synthesized when of 1.1 mol% (with respect to the Pt concentration) was added into the solution. Platinum octahedrons were synthesized when 32 mol% (with respect to the Pt concentration) was added into the solution. These results demonstrate that the metal salt , effectively controlled the relative growth rates of each facet of Pt nano particles.

In this study, Platinum(Pt) nanoparticles were synthesized by using polyol process which is one of the liquid phase reduction methods. Dihydrogen hexachloroplatinate (IV) hexahydrate , as a precursor, was dissolved in ethylene glycol and silver nitrate () was added as metal salt for shape control of Pt particle. Also, polyvinylpyrrolidone (PVP), as capping agent, was added to reduce the size of particle and to separate the particles. The size of Pt nanoparticles was evaluated particle size analyzer (PSA). The size and morphology of Pt nanoparticles were observed by transmission electron microscopy (TEM) and high resolution TEM (HRTEM). Synthesized Pt nanoparticles were studied with varying time and temperature of polyol process. Pt nanoparticles have been successfully synthesized with controlled sizes in the range 5-10 and 20-40 nm with cube and multiple-cube shapes.

Purpose : In this study, we manufactured functional contact Jens using 2-hydroxyethyl methacrylate, N-vinyl-2-pyrrolidone, methyl methacrylate and nano Au, platinum with antibiosis. Methods : The resulting mixture was copolymerized by heating at 70"C for about 40 minutes, at 80"C for about 40 minutes, and finally at wo·c for about 40 minutes. Results : The physical properties of the produced polymers were measured as followings. The refractive index of 1.431-1.432, water content of 38.58-39.53%, visible transmittance of 89.8- 91.5%, and oxygen transmissibility of 6.5934 xl0-9 cm/s ml Oz/ml xmmHg were obtained. Conclusions : In this study, we manufactured high-performance ophthalmic material containing nano gold and pJatinum which could protect eye from envirorunental factors. lt is judged that functional polymer materia! with the physical properties required to produce contact Jens was made.

Aluminum tri-butoxide was mixed with the water/ethanol solution and then chloroplatinic acid was added to the solution. The solution was dried at 100℃ for 15hrs to remove the solvent and water then it was calcined at 500℃. The catalyst was activated with a gas mixture. During the activation, the temperature was increased from 150℃ to 500℃. The necessary amount of urea was dissolved in 50mL water and injected. Aqueous urea solution was then mixed with the feed gas stream. At low temperatures, nitrogen containing compounds of urea decomposition are used as reductants in the reducton of NOX. However at high temperatures the nitrogen containing compounds are oxidized to NO and NO2 by oxygen instead of being used in the reduction. The activity of the catalyst was dependent on urea concentration in the feed stream when there was not adequate water vapor in the feed. The maximum conversion was shifted from 250℃ to 150℃ when water concentration was increased from 2 to 17%. It seems that the maximum temperature shifts to lower temperatures because the hydrolysis rate of HNCO increases with water, resulting in higher amounts of NH3.

A bulk porous composite with plantinum nano-dispersion was synthesized in air atmosphere through the combination of several in situ reactions, including the pyrolysis of . A mixture of (dolomite), , and LiF (0.5 wt%, as an additive) was cold isostatically pressed at 200 MPa and sintered at for 2 h. The porous composite ( : Pt=99 : 1 in volume) had a uniformly open-porous structure (porosity: 56%) with three-dimensional (3-D) network and a narrow pore-size distribution, similarly to the porous composites reported before. Catalytic Properties (viz., NO direct decomposition and NO reduction by ) of the composite were investigated up to . In the absence of oxygen, the NO conversion rate reached ~52% for the direct decomposition and ~100% for the reduction by , respectively. The results suggest the possibility of the porous composite as a multifunctional filter, i.e., simultaneous hot gas-filtering and in one component.

Combustion of ethanol (EtOH) at low temperatures has been studied using titania- and silica-supported platinum nanocrystallites with different sizes in a wide range of 1~25 nm, to see if EtOH can be used as a clean, alternative fuel, i.e., one that does not emit sulfur oxides, fine particulates and nitrogen oxides, and if the combustion flue gas can be used for directly heating the interior of greenhouses. The results of H2-N2O titration on the supported Pt catalysts with no calcination indicate a metal dispersion of 0.97±0.1, corresponding to ca. 1.2 nm, while the calcination of 0.65% Pt/SiO2 at 600 and 900℃ gives the respective sizes of 13.7 and 24.6 nm when using X-ray diffraction technique, as expected. A comparison of EtOH combustion using Pt/TiO2 and Pt/SiO2 catalysts with the same metal content, dispersion and nanoparticle size discloses that the former is better at all temperatures up to 200℃, suggesting that some acid sites can play a role for the combustion. There is a noticeable difference in the combustion characteristics of EtOH at 80~200℃ between samples of 0.65% Pt/SiO2 consisting of different metal particle sizes; the catalyst with larger platinum nanoparticles shows higher intrinsic activity. Besides the formation of CO2, low-temperature combustion of EtOH can lead to many other pathways that generate undesired byproducts, such as formaldehyde, acetaldehyde, acetic acid, diethyl ether, and ethylene, depending strongly on the catalyst and reaction conditions. A 0.65% Pt/SiO2 catalyst with a Pt crystallite size of 24.6 nm shows stable performances in EtOH combustion at 120℃ even for 12 h, regardless of the space velocity allowed.

A novel pretreatment technique was applied to the conventional Pt/alumina catalyst to prepare for the highly efficient catalyst for the preferential oxidation of carbon monoxide in hydrogen-rich condition. Their performance was investigated by selective CO oxidation reaction. CO conversion with the oxygen-treated Pt/Alumina catalyst increased remarkably especially at the low temperature below 100℃. This result is promising for the normal operation of the proton exchange membrane fuel cell (PEMFC) without CO poisoning of the anode catalyst. XRD analysis results showed that metallic Pt peaks were not observed for the oxygen-treated catalyst. This implies that well dispersed small Pt particles exist on the catalyst. This result was confirmed by high resolution transmission electron microscopy (HRTEM) analysis. Consequently, it can be concluded that highly dispersed Pt nanoparticles could be prepared by the novel pretreatment technique and thus, CO conversion could be increased considerably especially at the low temperatures below 100℃.