• Title/Summary/Keyword: surface characterization

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Hydrothermal Pressure Effect over Preparation of MoS2: Catalyst Characterization and Direct Methanation (수열 압력 제조 조건이 MoS2 촉매 특성과 직접 메탄화 반응에 미치는 영향)

  • PARK, JEONGHWAN;KIM, SEONGSOO;KIM, JINGUL
    • Journal of Hydrogen and New Energy
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    • v.29 no.2
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    • pp.170-180
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    • 2018

  • After $MoS_2$ catalyst was prepared at 1, 30, and 70 atm, the hydrothermal pressure effect over preparation of $MoS_2$ was investigated in terms of catalyst characterization and direct methanation. Multifaceted characterization techniques such as XRD, BET, SEM, TPR, EDS, and XPS were used to analyze and investigate the effect of high pressure over the preparation of surface and bulk $MoS_2$ catalyst. Result from XRD, SEM, and BET demonstrated that $MoS_2$ was more dispersed as preparation pressure was increased, which resulted finer $MoS_2$ crystal size and higher surface area. EDS result confirmed that bulk composition was $MoS_2$ and XPS result showed that S/Mo mole ratio of surface was about 1.3. TPR showed that $MoS_2$ prepared at 30 atm possessed higher active surface sites than $MoS_2$ prepared at 1 atm and these sites could contribute to higher CO yield during methanation. Direct methanation was used to evaluate the CO conversion of the both catalysts prepared at 1 atm and 30 atm and reaction condition was at feed mole ratio of $H_2/CO=1$, GHSV=4800, 30 atm, temperature($^{\circ}C$) of 300, 350, 400, and 450. $MoS_2$ prepared at 30 atm showed more stable and higher CO conversion than $MoS_2$ prepared at 1 atm. Faster deactivation was occurred over $MoS_2$ prepared at 1 atm, which indicated that preparation pressure of $MoS_2$ catalyst was the dominant factor to improve the yield of direct methanation.

  • https://doi.org/10.7316/KHNES.2018.29.2.170 인용 PDF KSCI

Electrochemistry Characterization of Metal Using Corrosion Inhibitors Containing Amide Functional Group (아미드 작용기를 가진 부식억제제를 사용한 금속의 전기화학적 특성)

  • Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.1
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    • pp.48-56
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    • 2011

  • In this study, we investigated the C-V diagrams and metal surface related to the electrochemistry characterization of metal(nickel, SUS-304). We determined electrochemical measurement by using cyclic voltammetry with a three-electrode system. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650 mV and measured to the initial point. The scan rate were 50, 100, 150, 200 and 250 mV/s. As a result, the C-V characterization of metal using N,N-dimethylacetamide and N,N-dimethylformamide inhibitors appeared irreversible process caused by the oxidation current from the cyclic voltammogram. After adding organic corrosion inhibitors, adsorption film constituted, and the passive phenomena happened. According to the results by cyclic voltammetry method, it was revealed that the addition of inhibitors containing amide functional group enhances the corrosion resistance properties.

  • https://doi.org/10.12925/jkocs.2011.28.1.8 인용 PDF KSCI