• 공업화학
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• 제3권3호
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• pp.527-534
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• 1992

Raney nickel 촉매를 이용하여 알칼리형 연료전지의 수소극을 제작하였다. $700^{\circ}C$에서 소결한 Raney nickel로 제작한 수소극의 경우 가장 좋은 전극성능을 갖는 $450mA/cm^2$의 전류밀도를 나타냈으며 이때의 평균촉매입자 크기는 $90{\AA}$이었다. CO-chemisorption 측정 및 분극곡선과 Tafel slope를 통하여 PTFE의 첨가량에 대한 전극의 전기화학적 성능을 고찰하였다. CO-chemisorption 측정 결과 5wt%의 PTFE가 첨가되었을 때 최고값을 갖는 것이 확인되었으나 전극에서의 전류밀도와 Tafel slope를 비교한 결과 10wt%의 PTFE를 첨가하는 경우가 가장 적당함을 알았다. Raney nickel제조시 nicke과 aluminum의 함량비는 60:40의 경우에 가장 좋은 전극 특성을 나타내었으며 담지량은 $0.25g/cm^2$의 경우가 적당하였다. 전극제조시 촉매층의 press압 및 촉매층과 기체확산층과의 접합시의 Press압에 대한 영향도 검토하였다. 또한 촉매의 표면 구조를 SEM으로 관찰하였으며 활성화시간 및 열처리 온도 등 여러가지 조건에 대한 전극의 영향도 고찰하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2001년도 제21회 학술발표회 초록집
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• pp.141-141
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• 2001

• 대한화학회지
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• 제49권1호
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• pp.29-34
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• 2005

• Journal of Applied Biological Chemistry
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• 제44권4호
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• pp.163-166
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• 2001

Piezoelectric (PZ) crystal biosensor system was used to detect the DNA of food pathogenic Listeria monocytogenes. L. monocytogenes-specific DNA was multiplied via the polymerase chain reaction using LM1 oligonucleotide (5'-TTACGAATTAAAAAGGAGCG-3') and LM2 oligonucleotide (5'-TTAAATCAGCAGGGGTCTTT-3') as primers. DNA fragment of 161 bp, which was specific only for L. monocytogenes, was observed. To obtain a large amount of single-stranded DNA containing an SH group used for coupling to the gold electrode chemisorptively, LM1 oligonucleotide containing a mercaptohexyl group was utilized as a single strand PCR primer. The PCR product was immobilized onto the gold electrode of PZ crystal, and hybridization was monitored in quartz crystal microbalance (QCM) system by injecting the antisense single-stranded DNA of 161 nucleotides obtained via the single strand PCR using the unmodified LM2 primer. Approximately 70 Hz of frequency drop was observed in the QCM system in the case of two consecutive injections of $5{\mu}g$ of the antisense single-stranded DNA.

• 한국대기환경학회지
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• 제16권5호
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• pp.529-537
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• 2000

Several Pt-based oxidation catalysts with different loading were prepared with various metal precursor solutions and characterized with H$_2$ chemisorption and TEM for Pt particle size. V was added to Pt-based catalyst for inhibiting SO$_2$oxidation reaction, as result, Pt-V/Ti-Si catalyst prepared by ERMS(Free Reduced Metal in Solution) method showed high enough activity and better inhibition on SO$_2$oxidation than Pt only catalyst. Optimum Pt particle size for diesel oxidation reaction turned out to be the size of around 20 nm. A prototype catalyst was prepared for light=duty diesel passenger car, and teated for the emission reduction performance with Korean regulation test mode(CVS-75 mode) on chassis dynamometer. The catalyst shows the performance reduction of 75~94% for CO, 53~67% for HC and 10~31% for PM. In the case of heavy-duty diesel catalyst, the domestic formal regulation teat mode D-13 was adopted for both Na engine and Turbo engine. The conversions of CO and THC are high enough(86% and 41%) while the reductions of NOx and PM are relatively low(3~11%).

• 공업화학
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• 제8권2호
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• pp.191-196
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• 1997

$Pt/MoO_3/SiO_2$ 촉매계에서의 $50^{\circ}C$ 등온 환원 실험에서 hydrogen spillover는 소성 온도가 증가함에 따라 더욱 빠른 속도로 진행된다. 이는 Pt 표면위에 형성되는 overlayer에 기인하는 것임을 TEM과 CO chemisorption 측정으로 알 수 있었다. 1-butene의 iso-butene으로의 골격이성질화 반응 mechanism은 carbonium ion의 형성과 methyl기의 골격 치환의 2 step으로 알려져 있다. $Pt/MoO_3/SiO_2$ 촉매계에서 약 $250^{\circ}C$에서 calcination하면 iso-butene 수율이 증가한다. 이는 $PtCl_x$ precursor 내에 존재하는 chlorine의 감소에 의한 것과 overlayer 생성에 따라 Pt 표면으로부터 $MoO_3/SiO_2$로의 hydrogen spillover의 증가에 의한 것으로 추측된다.

• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1785-1792
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• 2003

Zirconia modified with $MoO_3$ was prepared by impregnation of powdered $Zr(OH)_4$ with ammonium heptamolybdate aqueous solution followed by calcining in air at high temperature. Spectroscopic studies on prepared catalysts were performed by using FTIR, Raman, XRD, and DSC and by measuring surface area. Upon the addition of molybdenum oxide to zirconia up to 15 wt%, the specific surface area increased in proportion to the molybdate oxide content, while acidity measured by irreversible chemisorption of ammonia exhibited a maximum value at 3 wt% of $MoO_3$. Since the $ZrO_2$ stabilizes the molybdenum oxide species, for the samples equal to or less than 30 wt%, molybdenum oxide was well dispersed on the surface of zirconia and no phase of crystalline $MoO_3$ was observed at any calcination temperature above $400^{\circ}C$. The catalytic activities for cumene dealkylation were roughly correlated with the acidity of catalysts measured by ammonia chemisorption method, while the catalytic activities for 2-propanol dehydration were not correlated with the acidity because weak acid sites are necessary for the reaction.

• 한국안전학회지
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• 제8권1호
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• pp.29-34
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• 1993

Two major hazardous gases. SOx and NOx. are emissioned from fossile fuels. SOx has been removed when oil is refined but NOx hasn't. So NOx is very serious problem in air pollution now There are several technologies to remove NOx. e.g. cooling method. scrubbers method. combustion method, polymer membrane method and adsorbent methods. Polymer membrane and adsorbent methods have good economic merit in removal systems of low content hazard gases. Traditional absorbents are porous silicas, aluminas. active carbon and zeolites. But these absorbents act only physisorption which has less removal performance than chemisorption. In this study. polymeric absorbent which has chemisorption as well as physisorption was analyzed about chemical structure and experimented about optimum operation conditions. The results showed that the chemical structure of the polymeric absorbent was expected as polystyrene having -N-CH$_2$COOH absorbent was revealed about 310$m^2$/g. The molar ratio of absored NO to charged NO in absorption experiments was shown 60% of the polymeric absorbent and 45% of zeolite absorbent at 3$0^{\circ}C$.

• 공업화학
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• 제30권5호
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• pp.562-568
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• 2019

Cylindrical shape extrudates of calcium silicate hydrate (CSH) were prepared using different percentages of polyvinyl alcohol (PVA) / sodium alginate (SA) mixtures as binders and an aqueous solution containing 6% $H_3BO_3$ and 3% $CaCl_2$ was used as a cross linking agent. As the quantity of alginate increases, the phosphate removal efficiency and capacity were decreased. Among four different extrudate samples, the sample prepared by 8% PVA + 2% SA showed the highest phosphate removal efficiency (59.59%) and capacity (29.97 mg/g) at an initial phosphate concentration of 100 ppm and 2.0 g/L adsorbent dosage. Effects of the adsorbent dosage, contact time and initial phosphate concentration on the sample were further studied. The removal efficiency and capacity obtained by a 4.0 g/L adsorbent dose at an initial phosphate concentration of 100 ppm in 3 h were 79.38% and 19.96 mg/g, respectively. The experimental data of kinetic and isotherm measurements followed the pseudo-second-order kinetic equation and Langmuir isotherm model, respectively. These results suggested that the phosphate removal was processed via a chemisorption and a monolayer coverage of phosphate anions was on the CSH surface. The maximum adsorption capacity ($q_{max}$) was calculated as 23.87 mg/g from Langmuir isotherm model.

• 공업화학
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• 제28권1호
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• pp.50-56
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• 2017

포름알데하이드는 무색, 무취의 유독성 물질로 다양한 방법을 통하여 포름알데하이드를 제거할 수 있는 방법들이 많이 보고되었다. 본 논문에서는 생물학적 효소 반응 및 화학적 흡착 촉매 반응에 의한 포름알데하이드의 제거 효율을 비활성을 통해 비교하였다. 첫째, Escherichia coli K12포름알데하이드 탈수소화 효소(Formaldehyde dehydrogenase, FDH)를 Escherichia coli BL21(DE3)에 클로닝하여 발현 및 분리하였다. FDH 효소 활성($k_{cat}/K_m$)은 $2.49{\times}10^3sec^{-1}mM^{-1}$로 측정되었으며, 비활성은 8.69 U/mg으로 측정되었다. 둘째, 화학적 흡착 및 화학 촉매를 이용한 포름알데하이드의 제거 효율도 동시에 진행하였다. 본 논문에서는 활성탄과 제올라이트, KI 및 KOH로 처리한 활성탄과 제올라이트를 화학적 포름알데하이드 흡착제로 사용하였으며 $Pd/TiO_2$ 산화 촉매를 이용하여 포름알데하이드의 산화 반응 효율을 결정하였다. 결론적으로 본 논문에서 수행한 화학적 흡착 및 산화 촉매 반응의 경우 대략 50%의 비슷한 수준의 포름알데하이드 제거 효율을 보였으며, 특히 비활성의 경우 탈수소화효소의 비활성이 0.01-0.26 U/g 수준의 화학적 흡착 및 산화 촉매보다 월등히 높게 측정되었다.