Stabilization of Hydrogen Production via Methanol Steam Reforming in Microreactor by Al₂O₃ Nano-Film Enhanced Catalyst Adhesion

Jeong, Heondo,Na, Jeong-Geol,Jang, Min Su,Ko, Chang Hyun American Scientific Publishers 2016 Journal of nanoscience and nanotechnology Vol.16 No.5

<P>In hydrogen production by methanol steam reforming reaction with microchannel reactor, Al2O3 thin film formed by atomic layer deposition (ALD) was introduced on the surface of microchannel reactor prior to the coating of catalyst particles. Methanol conversion rate and hydrogen production rate, increased in the presence of Al2O3 thin film. Over-view and cross-sectional scanning electron microscopy study showed that the adhesion between catalyst particles and the surface of microchannel reactor enhanced due to the presence of Al2O3 thin film. The improvement of hydrogen production rate inside the channels of microreactor mainly came from the stable fixation of catalyst particles on the surface of microchannels.</P>

조촉매가 담지된 Ni/HY 촉매상에서 메탄의 건식 개질 반응 연구

정헌도(Heondo Jeong) 한국청정기술학회 2017 청정기술 Vol.23 No.2

HY 제올라이트에 담지된 Ni 촉매 및 Mg, Ca, K 그리고 Mn 등이 조촉매로 함께 담지된 Ni/HY 촉매상에서 메탄의 건식 개질반응을 수행하였다. 촉매는 초기 함침법으로 제조하였으며 제조된 촉매는 XRD, BET, SEM 및 TGA 분석을 통하여 반응 전후 의 촉매 변화를 고찰하였다. Ni의 담지량이 증가함에 따라 메탄의 전환율 및 생성물의 수율이 증가하였으며 Ni의 담지량이 13 wt% 일 때 메탄의 전환율이 최대를 나타내었다. Mg를 조촉매로 함께 담지하였을 때 촉매의 탄소에 대한 저항성이 크게 증가하였으며 이에 따라 촉매의 장기 안정성이 크게 향상되었다. 이는 조촉매로 담지된 Mg가 Ni의 입자 크기를 작게 하여 Ni의 분산도를 향상시키고 촉매의 비활성화를 방지하기 때문인 것으로 나타났다. Dry reforming of methane to synthesis gas was investigated over a series of Ni/HY catalysts promoted by Mg, Ca, K and Mn. These catalysts were characterized by XRD, BET, SEM, and TGA analyses before and after the reaction. Conversions and product yields were increased with increasing nickel loading up to 13 wt%. Among the catalysts tested in this work, the Ni-Mg/HY catalyst showed the highest carbon resistance and the most stable catalytic performance. It was revealed that the addition of Mg promoter reduced the nickel particle size and produced the highly dispersed nickel particles, and consequently, retarded the catalyst deactivation.

Hydrogen production by the photocatalytic overall water splitting on NiO/_Sr3_Ti2_O7: Effect of preparation method

Jeong, Heondo,Kim, Taehwan,Kim, Dongsik,Kim, Kweonill Elsevier 2006 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.31 No.9

<P><B>Abstract</B></P><P><SUB>Sr3</SUB><SUB>Ti2</SUB><SUB>O7</SUB>, which was known to a Ruddlesden–Popper phase as a layered perovskite-type oxide, was synthesized by the solid-state reaction method (SSRM) and polymerized complex method (PCM) in order to decompose pure water into hydrogen and oxygen without any co-catalyst. Under ultra-violet (λ<400nm) irradiation, <SUB>Sr3</SUB><SUB>Ti2</SUB><SUB>O7</SUB> catalyst prepared by the PCM was found to show promising results compared with that prepared by SSRM. When Ni was loaded onto <SUB>Sr3</SUB><SUB>Ti2</SUB><SUB>O7</SUB> catalyst prepared by the PCM, this photocatalytic activity drastically increased. The highest activity was obtained by the loading of 3wt.% of Ni. Moreover catalyst prepared by the PCM was also found to improve the stability of catalytic activity against long periods of photoirradiation.</P>

고체산 촉매상에서 FT WAX의 수소첨가 분해반응에 의한 중질유 생산

정헌도(Jeong, Heondo),정헌(Jung, Heon) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06

Fisher-Tropsch 반응을 통하여 생성되는 왁스는 황 또는 질소 성분을 포함하지 않으며 또한 방향족 및 중금속 성분이 없기 때문에 청정 수송유로써 사용이 가능하다는 장점이 있다. 그러나 Fisher-Tropsch 왁스는 그 분자량이 매우 큰 사슬형 탄화수소이기 때문에 수소첨가 분해반응을 통하여 중질유 range의 탄소수를 갖는 탄화수소로의 전환 기술이 반드시 필요하다. 이러한 수소첨가 분해반응에 사용되는 촉매는 강한 산점을 지니고 있는 양이온 교환 지르코니아가 대표적이라 할 수 있는데 최근 들어 강한 산점과 높은 산밀도, 그리고 기공의 모양과 크기에 따라 특정 반응이 제어되거나 활성화되는 형상선택성을 가지고 있기 때문에 다양한 반응에 촉매로 사용되는 제올라이트에 Pt 등의 귀금속을 담지한 촉매를 사용하여 Fisher-Tropsch 왁스의 전환율 및 중질유분의 선택도를 높이는 기술에 대한 연구가 활발히 진행되고 있다. 따라서 본 연구에서는 다양한 제올라이트 촉매에 귀금속을 담지하여 촉매를 제조하고 1L 급 고압 배치형 반응기를 이용하여 Fisher-Tropsch 왁스의 수소첨가 분해반응에 의한 중질유 제조 실험을 수행하고 그 결과를 고찰하였다.

Hydrogen evolution performance of magnesium alanate prepared by a mechanochemical metathesis reaction method

In Kyu Song,Heondo Jeong,Tae Hwan Kim,Ko Yeon Choo 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.2

Solvent-free magnesium alanates were prepared by a mechanochemical metathesis reaction method (ball milling method) with a variation of milling time. For the purpose of comparison, magnesium alanate was also prepared by metathesis reaction method in the presence of diethyl ether. The formation of magnesium alanate (Mg(AlH4)2) and magnesium alanate-diethyl ether (Mg(AlH4)2·Et2O) adduct was confirmed by XRD measurements. In both magnesium alanates, hydrogen evolution occurred in the first step decomposition. The starting temperature for hydrogen evolution of the solvent-free magnesium alanates decreased with increasing milling time, whereas the amount of hydrogen evolution of the solvent-free magnesium alanates increased with increasing milling time. The maximum amount of hydrogen evolution of the Mg(AlH4)2·Et2O adduct was slightly larger than that of the solvent-free Mg(AlH4)2, but the starting temperature for hydrogen evolution of the Mg(AlH4)2·Et2O adduct was much higher than that of the solventfree Mg(AlH4)2. The addition of a small amount of titanium to the solvent-free Mg(AlH4)2 greatly reduced the hydrogen evolution temperature of titanium-doped Mg(AlH4)2. However, the maximum amount of hydrogen evolution of the titanium-doped Mg(AlH4)2 was smaller than that of the solvent-free Mg(AlH4)2.

Bifunctionality of Cu/ZnO catalysts for alcohol-assisted low-temperature methanol synthesis from syngas: Effect of copper content

Kim, Ilho,Lee, Gihoon,Jeong, Heondo,Park, Jong Ho,Jung, Ji Chul Elsevier 2017 Journal of energy chemistry Vol.26 No.3

<P>Alcohol-assisted low-temperature methanol synthesis was conducted over Cu/ZnO_X catalysts while varying the copper content (X). Unlike conventional methanol synthesis, ethanol acted as both solvent and reaction intermediate in this reaction, creating a different reaction pathway. The formation of crystalline phases and characteristic morphology of the co-precipitated precursors during the co-precipitation step were important factors in obtaining an efficient Cu/ZnO catalyst with a high dispersion of metallic copper, which is one of the main active sites for methanol synthesis. The acidic properties of the Cu/ZnO catalyst were also revealed as important factors, since alcohol esterification is considered the rate-limiting step in alcohol-assisted low-temperature methanol synthesis. As a consequence, bifunctionality of the Cu/ZnO catalyst such as metallic copper and acidic properties was required for this reaction. In this respect, the copper content (X) strongly affected the catalytic activity of the Cu/ZnO_ X catalysts, and accordingly, the Cu/ZnO_0.5 catalyst with a high copper dispersion and sufficient acid sites exhibited the best catalytic performance in this reaction. (C) 2017 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.</P>

DEHYDRATION OF 1-OCTANOL OVER ALUMINA CATALYST FOR THE PRODUCTION OF 1-OCTENE

Young-eun KIM,Un Ho JUNG,Min Hye YOUN,Heondo JEONG,Dong Hyun CHUN,Ji Chan Park,Ki Bong LEE,Kee Young KOO 한국신재생에너지학회 2017 AFORE Vol.2017 No.11

Preparation of Cu/ZnO catalyst using a polyol method for alcohol-assisted low temperature methanol synthesis from syngas

Jong-Ho Park,정지철,Yeojin Jeong,Ji Yeon Kang,Ilho Kim,Heondo Jeong,Jongki Park 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.1

A polyol method was used to prepare Cu/ZnO catalysts for alcohol-assisted low temperature methanol synthesis from syngas. Unlike conventional low temperature methanol synthesis, ethanol was employed both as a solvent and a reaction intermediate. Catalyst characterization revealed that Cu/ZnO catalysts were successfully and efficiently prepared using the polyol method. Various preparation conditions such as PVP concentration and identity of ZnO precursor strongly influenced the catalytic activity of Cu/ZnO catalysts. Copper dispersion and catalyst morphology played key roles in determining the catalytic performance of the Cu/ZnO catalyst in alcohol-assisted low temperature methanol synthesis. A high copper dispersion and platelike Cu/ZnO structure led to high catalytic activity. Among the catalysts tested, 5_Cu/ZnO_Zn(Ac)2 had the best catalytic performance due to its high copper dispersion.