• Korean Chemical Engineering Research
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• 제61권3호
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• pp.341-347
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• 2023

PEMFC(Proton Exchange Membrane Fuel Cells)에서 PtCo/C 합금 촉매가 성능이나 내구성에서 우수하여 많이 사용되고 있다. 그러나 높은 전압에서(1.0~1.5 V) 평가되는 촉매 지지체 내구성에 관한 연구는 별로 보고 되지 않았다. 본 연구에서는 PtCo/C 촉매와 Pt/C 촉매에 촉매 지지체 가속 열화 프로토콜을 적용한 후 내구성을 비교하였다. 1.0↔1.5V 전압 변화 사이클 반복 후에 촉매 비활성도(Mass activity)와 전기화학적 활성면적(ECSA), 전기이중층 용량(DLC), Pt 용해와 입자 성장 등을 분석하였다. 전압변화 2,000 사이클 후 PtCo/C 촉매는 Pt/C 촉매에 비해 0.9 V에서 촉매 무게당 전류밀도가 1.5배 이상 감소하였다. 이와 같은 결과는 PtCo/C 촉매의 카본지지체의 열화 속도가 Pt/C 촉매보다 높기 때문이었다. Pt/C 촉매는 PtCo/C 촉매보다 촉매층의 ECSA 감소가 1.5배 이상 높았지만 Pt/C 촉매의 카본 지지체 부식이 작아 I-V 성능 감소가 작았다. PtCo/C 촉매의 고전압 내구성 향상을 위해서는 카본 지지체 내구성 향상이 필수적임을 보였다.

• 에너지공학
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• 제7권1호
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• pp.35-43
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• 1998

본 연구에서는 Pt/C와 Pt-Ru/C 촉매를 이용하여 직접메탄올 연료전지용 연료극 전극을 제조하고 전극 및 메탄올 산화 특성에 대하여 고찰하였다. 전극은 SEM, TEM 및 열중량 분석을 통하여 특성을 조사하였다. 메탄올의 산화 특성은 1M CH3OH+1M H2SO4 용액에서 정전위/정전류계를 이용하여 반전지 시험 및 순환 전압-전류법으로 조사하였다. 연구결과를 통하여 메탄올 산화전극은 촉매층 내에 PTFE가 20w% 포함되었을 경우가 백금촉매의 이용률이 높고 우수한 성능을 보여 주었다. Pt-Ru/C 이원촉매는 Pt/C 촉매에 비하여 메탄올 산화특성이 우수하고 성능이 우수한 촉매임을 알 수 있었다. Pt/Ru/C와 Pt/C 촉매를 이용하여 제조한 전극의 메탄올 산화반응에 대한 활성화 에너지는 11.60 kJ/mol과 26.85 kJ/mol이었다.

• 한국분말재료학회지
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• 제19권1호
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• pp.6-12
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• 2012

Electricity is generated by the combined reactions of hydrogen oxidation and oxygen reduction which occur on the Pt/C catalyst surface. There have been lots of researches to make high performance catalysts which can reduce Pt utilization. However, most of catalysts are synthesized by wet-processes and a significant amount of chemicals are emitted during Pt/C synthesis. In this study, Pt/C catalyst was produced by arc plasma deposition process in which Pt nano-particles are directly deposited on carbon black surfaces. During the process, islands of Pt nano-particles were produced and they were very fine and well-distributed on carbon black surface. Compared with a commercialized Pt/C catalyst (Johnson & Matthey), finer particle size, narrower size distribution, and uniform distribution of APD Pt/C resulted in higher electrochemical active surface area even at the less Pt content.

• Korean Chemical Engineering Research
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• 제61권2호
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• pp.189-195
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• 2023

PEMFC(고분자 전해질 막 연료전지) cathode 촉매로 Pt-Co/C가 내구성 향상 때문에 최근에 많이 사용되는 추세이다. 연료전지에서 전극과 전해질은 상호 간에 성능과 내구성 면에서 밀접하게 영향을 준다. Pt/C 전극 촉매에서 Pt-Co/C로 대체되었을 때 고분자 전해질막의 전기화학적 내구성에 미치는 영향에 대해서 연구하였다. PEMFC 고분자막의 전기화학적 가속 열화 과정에서 Pt-Co/C MEA(막전극접합체)의 내구성이 Pt/C MEA 내구성보다 높았다. FER (불소유출속도)와 수소투과도를 분석한 결과 Pt-Co/C MEA의 고분자막 열화속도가 Pt/C MEA보다 낮음을 보였다. OCV(개회로전압) holding 과정에서 Pt-Co/C 전극의 활성면적 감소속도가 Pt/C 전극보다 낮고, 고분자막에 석출되는 Pt 양도 Pt-Co/C MEA가 Pt/C MEA보다 작았다. 고분자막 내부의 Pt는 라디칼을 생성해서 고분자막을 열화시킴으로 Pt 석출 속도가 높은 Pt/C MEA의 고분자막 열화속도가 높게 나타났다. Pt-Co/C 촉매를 사용하면 전극 내구성도 향상되고, 고분자막에 석출되는 Pt양도 감소해서 고분자막의 전기화학적 내구성을 향상시켰다.

• 전기화학회지
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• 제17권3호
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• pp.201-208
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• 2014

본 연구에서는 산화그래핀과 카본블랙의 혼합담체를 이용하여 내구성이 향상된 백금촉매를 폴리올법으로 제조하였다. 삼전극 순환전압전류법을 이용한 전기화학성능 측정결과 적절한 비율로 조절된 혼합담지체에 백금을 담지시켰을 경우 초기 성능 감소없이 장기내구성이 향상되는 것으로 나타났다. 또한 회전원판전극을 이용하여 산소환원반응을 수행한 결과 혼합담체에 담지된 백금촉매가 카본블랙 단일담체에 담지된 백금촉매보다 우수한 고유활성값을 나타내었다.

• 한국환경과학회지
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• 제18권10호
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• pp.1071-1077
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• 2009

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 $100^{\circ}C$. 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 continued 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 $100^{\circ}C$.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.188-190
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• 2007

The MEA with the catalyst layer containing PtRu black and 60 wt. %Pt/C as their anode and cathode catalysts. For find to effect of carbon support, the MEA with platinum black for cathode catalyst was fabricated. The performance of the MEA with the catalyst layer containing (PtRu black:60 wt.% Pt/C) as their anode and cathode catalyst has shown competitively higher value than the performance of the MEA with the catalyst layer containing (PtRu black:Pt black) as their anode and cathode catalyst.

• 한국정밀공학회지
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• 제31권10호
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• pp.955-965
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• 2014

Transport phenomena of reactant and product are directly linked to intrinsic inhomogeneous random configurations of catalyst layer (CL) that consist of ionomer, carbon-supported catalyst (Pt/C), and pores. Hence, electrochemically active surface area (ECSA) of Pt/C is dominated by geometrical morphology of mass transport path. Undoubtedly these ECSAs are key factor of total fuel cell efficiency. In this study, non-deterministic micro-scale CLs were randomly generated by Monte Carlo method and implemented with the percolation process. To ensure valid inference about Pt/C catalyst utilization, 600 samples were chosen as the number of necessary samples with 95% confidence level. Statistic results of 600 samples generated under particular condition (20vol% Pt/C, 30vol% ionomer, 50vol% pore, and 20nm particle diameter) reveal only 18.2%~81.0% of Pt/C can construct ECSAs with mean value of 53.8%. This study indicates that the catalyst utilization in fuel cell CLs cannot be identical notwithstanding the same design condition.

• Bulletin of the Korean Chemical Society
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• 제32권10호
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• pp.3660-3665
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• 2011

CO-tolerant PtMo/C alloy electrocatalyst was prepared by a colloidal method, and its electrocatalytic activity toward CO oxidation was investigated. Electrochemical study revealed that the alloy catalyst significantly enhanced catalytic activity toward the electro-oxidation of CO compared to Pt/C counterpart. Cyclic voltammetry suggested that Mo plays an important role in promoting CO electro-oxidation by facilitating the formation of active oxygen species. The effect of Mo on the electronic structure of Pt was investigated using X-ray absorption spectroscopy to elucidate the synergetic effect of alloying. Our in-depth spectroscopic analysis revealed that CO is less strongly adsorbed on PtMo/C catalyst than on Pt/C catalyst due to the modulation of the electronic structure of Pt d-band. Our investigation shows that the enhanced CO electrooxidation in PtMo alloy electrocatalyst is originated from two factors; one comes from the facile formation of active oxygen species, and the other from the weak interaction between Pt and CO.

• 한국대기환경학회지
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• 제18권3호
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• pp.205-212
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• 2002

The catalytic combustion of benzene, toluene and xylene over Pt-based catalyst was investigated in a fixed bed flow reactor system with atmospheric pressure to recycle the waste industrial catalyst for the processes of removing volatile organic compounds. According to the pretreatment condition, the properties of the waste Pt-based catalyst were characterized by XRD (X-ray diffraction) and BET (Brunauer-Emmett-Toller). In the carte of air pretreatment, 20$0^{\circ}C$ was found to be optimal, and increasing pretreatment temperature resulted in the reduction of the catalytic activity. When Pt-based catalyst pretreated at 20$0^{\circ}C$ by alto was retreated by hydrogen, the catalytic activity increased by increasing treatment temperature. In the case of HNO$_3$aqueous solution pretreatment, the catalytic activity decreased by increasing the concentration of HNO$_3$aqueous solution. The catalytic activity was seen to observe the following sequence : benzene > toluene > xylene.