• Applied Chemistry for Engineering
• /
• v.7 no.5
• /
• pp.999-1005
• /
• 1996

Pt catalyst on carbon black was prepared by colloidal method, ion exchanging method and methanol reducing method. The colloidal method has been used generally. At ion exchanging method, $H^+$ of functional group on carbon surface made by oxidation treatment was exchanged with Pt ion. At methanol reducing method, Pt was impregnated on carbon to reduce by methanol contained with surfactants. With TEM and XRD, Pt particle size impregnated on carbon by various methods was $30{\sim}50{\AA}$. Loading yield was about 100%, loading yield of ion exchanging method was 99.92% by DCP analysis and 99.87% by combustion method. Within 60 hour, current density of oxygen reduction was $460mA/cm^2$ at 0.7V(vs. RHE) at colloidal method. It was the better performance than catalyst prepared by ion exchanging, methanol reducing method. But, it was shown some decrease of performance for long operation time(after 100hour), catalyst prepared by methanol reducing method was shown stable performance.

• Resources Recycling
• /
• v.28 no.2
• /
• pp.46-53
• /
• 2019

In this study, the extraction and reduction behavior of platinum group metals in a non-aqueous solvent based on ionic liquids was investigated in order to confirm a new extraction technology of platinum group metals. Platinum was selectively extracted using an ionic liquid $[C_4mim]PF_6$ from a mixed solution of $PdCl_2$, $PtCl_4$ and $RhCl_3$ dissolved with concentration ratio of 10:1:0.5 M. After stripping of the metals by 1 M $HNO_3$ solution, the platinum was preferentially reduced by aqueous electrolysis on gold electrode at -0.8 V (vs. Pt-QRE). The residual palladium and rhodium were transferred to ionic liquid of $[C_4mim]Cl$. The metallic palladium and rhodium could be sequentially reduced on gold and STS304 as working electrodes by non-aqueous electrolysis, respectively.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.12 no.5
• /
• pp.26-34
• /
• 2008

The performance of several catalysts to decompose the high test peroxide (HTP) was described in this paper. Manganese oxide, Platinum and Iridium were coated on the gamma alumina. The catalyst activity as active materials was measured at the flask reactor. The response time of various catalysts was also measured with a 50 Newton class thruster. $Ir/Al_2O_3$ that showed the best activity in the flask reactor and response time at the thruster, failed the reaction when continuous mode test was carried out with the thruster. $Pt/Al_2O_3$ and $MnO_2/Al_2O_3$ can be substitutes to decompose the HTP. In addition, for larger thruster, $MnO_2/Al_2O_3$ can be a good catalyst because its cost is below 5 % of $Pt/Al_2O_3$.

• Korean Chemical Engineering Research
• /
• v.56 no.5
• /
• pp.705-710
• /
• 2018

An electrochemical glucose sensor with enzyme-free was fabricated using Pt nanoparticles (Pt NPs) decorated CuO nanoflowers (CuO NFs). 3-D CuO nanoflowers film was directly synthesized on Cu foil by a simple hydrothermal method and Pt NPs were dispersed on the petal surface of CuO NFs through electrochemical deposition. This prepared sample was noted to Pt NPs-CuO NF. Morphology of the Pt NPs-CuO NFs layer was analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The electrochemical properties and sensing performances were investigated using cyclic voltammetry (CV) and chronoamperometry (CA) under alkaline condition. The sensor exhibited a high sensitivity, wide liner range and fast response time. Its excellent sensing performance was attributed to the synergistic effect of the Pt NPs and CuO nanostructure.

• Clean Technology
• /
• v.22 no.2
• /
• pp.82-88
• /
• 2016

The loss of activity by coke is an important cause of catalyst deactivation during industrial operation. In this study, hydrogen ratio of reaction condition, which has influenced on coke formation over Pt-Sn catalyst, and regeneration of catalysts activity by coke burning, Pt sintering of coke burning as coke contents, effects of coke formation and deactivation with different Sn contents were confirmed. Pt-Sn-K catalyst supported on θ-alumina and γ-alumina was prepared progressively. Activity of regenerated catalyst for propane dehydrogenation was compared with fresh catalyst by coke burning, after propane dehydrogenation was carried out with different hydrogen ratio at 620 ℃ on fresh catalyst. Regenerated catalyst’s physical characterization such as BET, coke analysis and XRD was investigated. Through catalytic activity test and characterization, Sn contents of catalyst and hydrogen ratio in feed stream could affect coke formation on catalyst surface. Excessive coke makes loss of activity and Pt sintering during air regeneration process.

• 한국전기화학회:학술대회논문집
• /
• 2002.07a
• /
• pp.139-146
• /
• 2002

본 연구에서는 고분자 전해질 연료전지(PEMFC)용 전극 슬러리 조성변화가 막전극접합체(MEA)의 전극 특성에 미치는 영향을 조사하였다. 전극촉매의 구성 성분인 Nafion의 함량을 변화시켜 전극 성능의 최적 함량을 고찰하였고, 백금의 함침량의 변화에 따른 전극 성능을 고찰하였다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2003.08a
• /
• pp.148-148
• /
• 2003

• Resources Recycling
• /
• v.21 no.3
• /
• pp.15-20
• /
• 2012

In this paper, we carried out separation of membrane and leaching of Pt and Ru using hydrochloric acid from MEA(membrane-electrode assembly) of fuel cell. In this method, these were separated from MEA of fuel cell using the distilled water, 10 vol.% butanol solution and 15 vol.% cationic surfactant(Koremul-LN-7) by dipping method without the dispersion of catalyst particles. And the leaching of Pt and Ru containing in the separated carbon paper catalysts has been studied by hydrochloric acid using $HNO_3$ or $H_2O_2$ as a oxidant. The leaching ratio of Pt and Ru were higher when $H_2O_2$ was used as a oxidant and the optimum conditions were obtained in 8M HCl, the amount of $H_2O_2$ 5M and 6 hours of leaching time at $90^{\circ}C$. In this condition, extraction of Pt and Ru were 98% and 71.5%, respectively.

• Journal of Sensor Science and Technology
• /
• v.3 no.1
• /
• pp.32-39
• /
• 1994

Catalytic combustion type sensor was fabricated for alcohol detection, and its characteristics were tested. When the resistance of Pt coil for pellistor is 2.0 ohm, suggestible input power to bridge circuit was about 300 mW for methanol detection, and in the range from 350 mW to 400 mW for ethanol. Pellistors were prepared by means of impregnating Pt or Pd on the ${\gamma}$-alumina bead for sensing element, and transition metals such as $Co_{3}O_{4}$, $Fe_{2}O_{3}$ for compensating element.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.11a
• /
• pp.371-374
• /
• 2008

The performance of several catalysts to decompose the high test peroxide (HTP) was described in this paper. Manganese oxide, Platinum and Iridium were coated on the gamma alumina. The response time of various catalysts was measured with a 50 Newton class thruster. Ir/$Al_2O_3$ that showed the fastest response time at the thruster, failed the reaction when continuous mode test was carried out with the thruster. Pt/$Al_2O_3$ and MnO_2/Al_2O_3$ can be substitutes to decompose the HTP. In addition, for larger thruster, MnO_2/Al_2O_3$ can be a good catalyst because its cost is below 5 % of Pt/$Al_2O_3$.