Metal-organic frameworks (MOFs) are widely used in various fields because they make it easy to control porous structures according to combinations of metal ions and organic linkers. In addition, ZIF (zeolitic imidazolate framework), a type of MOF, is made up of transition metal ions such as Co2+ or Zn2+ and linkers such as imidazole or imidazole derivatives. ZIF- 67, composed of Co2+ and 2-methyl imidazole, exhibits both chemical stability and catalytic activity. Recently, due to increasing need for energy technology and carbon-neutral policies, catalysis applications have attracted tremendous research attention. Moreover, demand is increasing for material development in the electrocatalytic water splitting and metal-air battery fields; there is also a need for bifunctional catalysts capable of both oxidation/reduction reactions. This review summarizes recent progress of bifunctional catalysts for electrocatalytic water splitting and metal-air batteries using ZIF-67. In particular, the field is classified into areas of thermal decomposition, introduction of heterogeneous elements, and complex formation with carbonbased materials or polyacrylonitrile. This review also focuses on synthetic methods and performance evaluation.

Platinum (Pt) catalysts dispersed on carbon-based support materials are generally used in the polymer electrolyte membrane (PEM) fuel cells. In this study, commercial graphene nanoplatelets (GNPs), with different surface areas (320, 530, 800 m2 g− 1), were used as catalyst supports in PEM fuel cells. These GNPs were also pyrolyzed under the inert atmosphere, with and without melamine, as the nitrogen (N) source. Various characterizations (Elemental analysis, FTIR, Raman spectroscopy, BET, TEM, HRTEM, SAED, XRD, TGA, ICP-MS, contact angle measurement, CV, ORR, chronoamperometry, EIS, PEM fuel cell performance test) were performed for the detailed analysis of Pt/GNPs. Based on the three-electrode cell system, the lowest electrochemical surface area (ECSA) loss (29.9%), Pt mass activity loss (20.3%) and overall (charge and mass) resistance (42.2 Ω) were obtained with the Pt/M-530 catalyst. According to the in-situ PEM fuel cell performance results, the specific peak power density was recorded as (450 mW mg Pt− 1) for the Pt/R-530 catalyst, which has also the second most hydrophobic catalyst layer surface with the 146.5° ± 1.28° contact angle value. On the heels of Pt/R-530, the two best performances also belong to the Pt/M-530 (391 mW mg Pt− 1) and Pt/P-530 (378 mW mg Pt− 1) catalysts of the same group.

Multi-walled carbon nanotubes (MWCNTs) grown by chemical vapor deposition retain the residual catalyst particles from which the growth occurred, which are considered a detriment to MWCNTs’ performance, especially electrical conductivity. The first direct measurements have been made of the electrical transport through the catalyst cap into the MWCNT using nanoscale 2-point-probe to determine the effects of the catalyst particle’s size and the diameter ratio with its associated MWCNT on the electrical transport through the catalyst cap as compared to the inherent conductivity of the MWCNT. The MWCNT diameter is independent of the catalyst size, but the ratio of the catalyst cap diameter to MWCNT diameter (DC/DNT) determines the conduction mechanism. Where DC/DNT is greater than 1 the resulting I–V curve is near ohmic, and the conduction through the catalyst ( RC+NT) approaches that of the MWCNT (RNT); however, when the DC/DNT < 1 the I–V curves shift to rectifying and RC+NT > > RNT. The experimental results are discussed in relation to current crowding at the interface between catalyst and nanotube due to an increased electric field.

In this study, Fe–Mo–MgO catalysts for the synthesis of carbon nanotubes (CNTs) were prepared using the combustion method and CNTs were synthesized through catalytic chemical vapor deposition. The combustion time was controlled to 0.5, 1, 2, 3, 5, 10, and 24 h in the catalyst preparation stage. The residual carbon contents after the combustion stage and the morphologies of synthesized CNTs were also analyzed. The diameter, yield, and crystallinity of the synthesized CNTs were found to remarkably vary according to the combustion time in the catalyst preparation process. The amount of residual carbon in the catalyst considerably affects the purity, crystallinity, diameter and its distribution, and wall number of CNTs. Based on the yield and crystallinity, CNTs synthesized using the catalyst with a combustion time of 3 h were determined to be the most appropriate for application in field emitters

Bypass line과 Catalyst를 공간적으로 결합한 Bypass 일체형 탈질설비를 제안하였다. 탈질설비 내부에 설치되는 Bypass의 개폐장치 의 형태에 따른 Catalyst로의 유동 변화를 확인하기 위하여 상용프로그램인 Ansys Fluent를 사용하여 탈질설비를 모델링하고 시뮬레이션을 구성하였다. 탈질설비 내의 Catalyst로 인한 계산시간과 Mesh의 수를 줄이기 위해 Porous media방식으로 Catalyst를 모델링하였다. Catalyst로 의 입구각도와 Bypass 개폐장치의 크기를 변화시키면서 시뮬레이션을 수행하고 시뮬레이션의 결과로 Catalyst로의 유동 평균속도와 균일도의 변화를 확인하였다.

In this study, a manganese catalyst on the surface of a ceramic support was developed for the removal of odor emitted from barbecuing restaurants. Its ozone oxidation at room temperature was tested using acetaldehyde (CH3CHO), the most dominant compound in the barbecuing odor, and the ozonation efficiency under wet conditions was also studied. The manganese catalyst was made with the honeycomb-type ceramic support, and an acid pretreatment was applied to increase its specific surface area, resulting in an increase of the degree of dispersion of manganese oxide. The acetaldehyde removal efficiency using the manganese catalyst on the acidpretreated support (Mn/APS) increased by 49%, and the ozone decomposition rate and the CO2 conversion rate also increased by 41% and 27%, respectively. The catalyst without surface pretreatment (Mn/S) showed a low efficiency for the acetaldehyde ozonation, and other organic compounds such as acetic acid (CH3COOH) and nonanal (CH3(CH3)7CHO) were found as oxidation by-products. In comparison, CO2 was the most dominant product by the ozonation of acetaldehyde using the Mn/APS. When the relative humidity was increased to 50% in the influent gas stream, the acetaldehyde removal efficiency using the Mn/APS decreased, but only the production rates of CO2 and acetic acid were changed. As a result, the manganese oxide catalyst on the surface of the acid-pretreated honeycomb support manifested high acetaldehyde ozonation even at humid and room temperature conditions.

Continuous synthesis of high-crystalline carbon nanotubes (CNTs) is achieved by reconfiguring the injection part in the reactor that is used in the floating catalyst chemical vapor deposition (FC-CVD) process. The degree of gas mixing is divided into three cases by adjusting the configuration of the injection part: Case 1: most-delayed gas mixing (reference experiment), Case 2: earlier gas mixing than Case 1, Case 3: earliest gas mixing. The optimal synthesis condition is obtained using design of experiment (DOE) in the design of Case 1, and then is applied to the other cases to compare the synthesis results. In all cases, the experiments are performed by varying the timing of gas mixing while keeping the synthesis conditions constant. Production rate (Case 1: 0.63 mg/min, Case 2: 0.68 mg/min, Case 3: 1.29 mg/min) and carbon content (Case 1: 39.6 wt%, Case 2: 57.1 wt%, Case 3: 71.6 wt%) increase as the gas-mixing level increases. The amount of by-products decreases stepwise as the gas-mixing level increases. The IG/ID ratio increases by a factor of 7 from 10.3 (Case 1) to 71.7 (Case 3) as the gas-mixing level increases; a high ratio indicates high-crystalline CNTs. The radial breathing mode (RBM) peak of Raman spectrograph is the narrowest and sharpest in Case 3; this result suggests that the diameter of the synthesized CNTs is the most uniform in Case 3. This study demonstrates the importance of configuration of the injection part of the reactor for CNT synthesis using FC-CVD.

RHDS 촉매는 코크와 황 화합물 그리고 금속인 바나듐이 표면에 침적되어 비활성화가 된다. 이러한 오염물을 제거하기 위해서 먼저 폐 RHDS 촉매에 묻어있는 중질유분의 세정, 코크와 황 화합물을 고온 배소 처리한 후, 과량으로 침적되어 있는 바나듐의 침출량을 조절하기 위하여 0.5, 1 wt% 옥살산 수용액을 이용하여 초음파 교반기에서 50 ℃, 10 sec 동안 교반하여 NOx 저감을 위한 SCR 촉매로의 적용 가능성을 확인하고자 하였다. 재생처리 한 RHDS 촉매의 성분은 XRF 를 사용하여 분석하였고, 상압 고정층 연속 흐름 반응기 상에서 NOx 저감 성능을 측정하였다. 옥살산 수용액 0.5 wt%, 10 sec 동안 초음파 침출한 촉매가 가장 안 정적인 NOx 저감 성능을 보였으며, 375 ℃ 이상의 고온에서는 상용 촉매와 동등 수준의 NOx 저감 성능을 확인할 수 있었으나 저온영역 200 ℃에서 250 ℃까지는 상용 촉매보다 낮은 NOx 저감 성능을 보였다. 따라서 폐 RHDS 촉매를 재생처리 한 후 분말로 메탈 코로게이트 지지체에 워시코팅한 촉매는 상용 SCR 촉매로서 이용 가능함을 확인하였다.

(아이오도메틸)트리메틸실란을 이용한 2-에티닐피리딘의 무촉매 중합을 통하여 N-(트리메틸실릴메틸) 피리디늄 아이오다이드를 측쇄로 갖는 새로운 공액구조 고분자를 합성하였다. 이 중합반응은 불균일하게 진행되었으며 중합수율은 95%로 매우 높았지만 생성된 고분자는 중합중 가교화반응으로 대부분의 유기용매에 용해하지 않았다. 합성 고분자의 분자구조를 분석한 결과 이온성 피리딜 치환기를 갖는 해당 고분자가 합성 되었음을 확인할 수 있었다. 합성 고분자의 열적 특성과 몰폴로지 등을 TGA, EDX 등의 분석장비로 측정하고 분석하였다.

2-브로모에틸 에틸 에테르를 이용한 2-에티닐피리딘의 무촉매 중합을 통하여 측쇄에 에테르 부분을 갖는 새로운 공액구조 고분자를 합성하였다. 이 중합반응은 비교적 낮은 온도 조건에서도 균일하게 잘 진행 되었으며 89%의 수율로 해당 고분자를 합성할 수 있었다. NMR, IR, UV-visible 분광분석기 등을 이용하여 고 분자의 구조를 분석한 결과 설계한 치환기를 갖는 해당 고분자가 합성되었음을 확인할 수 있었다. 본 고분자는 물을 포함한 DMF, DMSO, DMAc, 메탄올 등의 유기 용매에 완전히 용해하였다. 합성 고분자의 전기화학적 특성과 광발광 특성을 측정하고 분석하였다.

This study investigated the degradation characteristics and biodegradability of phenol, refractory organic matters, by injecting MgO and CaO-known to be catalyst materials for the ozonation process-into a Dielectric Barrier Discharge (DBD) plasma. MgO and CaO were injected at 0, 0.5, 1.0, and 2 g/L, and the pH was not adjusted separately to examine the optimal injection amounts of MgO and CaO. When MgO and CaO were injected, the phenol decomposition rate was increased, and the reaction time was found to decrease by 2.1 to 2.6 times. In addition, during CaO injection, intermediate products combined with Ca2+ to cause precipitation, which increased the COD (chemical oxygen demand) removal rate by approximately 2.4 times. The biodegradability of plasma treated water increased with increase in the phenol decomposition rate and increased as the amount of the generated intermediate products increased. The biodegradability was the highest in the plasma reaction with MgO injection as compared to when the DBD plasma pH was adjusted. Thus, it was found that a DBD plasma can degrade non-biodegradable phenols and increase biodegradability.

This study focused on the development of Fe–Co/kaolin catalyst by a wet impregnation method. Response surface methodology was used to study the influence of operating variables such as drying temperature, drying time, mass of support and stirring speed on the yield of the catalyst. The catalyst composite at best synthesis conditions was then calcined in an oven at varied temperature and time using 22 factorial design of experiment. The catalyst with optimum surface area was then utilized to grow carbon nanofiber (CNF) in a chemical vapour deposition (CVD) reactor. Both the catalyst and CNF were characterized using high-resolution scanning electron microscopy, high-resolution transmission electron microscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy. On the influence of operating variables on the yield of catalyst, the results showed that an optimum yield of 96.51% catalyst was obtained at the following operating conditions: drying time (10 h), drying temperature (110 °C), stirring speed (100 rpm) and mass of support (9 g). Statistical analysis revealed the existence of significant interactive effects of the variables on the yield of the catalyst. The HRSEM/XRD/BET/TGA analysis revealed that the particles are well dispersed on the support, with high surface area (376.5 m2/g) and thermally stable (330.88 °C). The influence of operating parameters on the yield of CNF was also investigated and the results revealed an optimum yield of 348% CNF at the following operating conditions: reaction temperature (600 °C), reaction time (40 min), argon flow rate (1416 mL/min) and acetylene/hydrogen flow rate (1416 mL/ min). It was found from statistical analysis that the reaction temperature and acetylene/hydrogen flow rates exerted significant effect on the CNF yield than the other factors. The contour and surface plots bi-factor interaction indicated functional relationship between the response and the experimental factors. The characterization results showed that the synthesized CNF is thermally stable, twisted and highly crystalline and contain surface functional groups. It can be inferred from the results of various analyses that the developed catalyst is suitable for CNF growth in a CVD reactor.

본 연구에서는 기존 상용 SCR 촉매보다 비표면적, 경량성 및 온도 응답성이 우수한 SCR 촉매의 개발을 목적으로 바나듐과 텅스텐의 함량과 바인더의 첨가량을 달리하여 Metal foam 형태의 지지체에 코팅하여 SCR 촉매를 제조한 후, 실험실 규모의 마이크로 상압반응기상에서 공간속도별로 NOx 저감 성능을 측정하였다. 촉매의 특성은 Porosimeter, SEM(scanning electron microscope), EDX(energy dispersive x-ray spectrometer) 및 ICP(inductively coupled plasma), 실체현미경(Stereomicroscope) 기기를 이용하여 분석하였다. 연구 결과 NOx 저감 성능은 공간속도가 증가할수록 감소하였고, 바나듐과 텅스텐의 함량이 3.5 wt.% 일 때 가장 우수한 것으로 확인하였다. 또한, 바인더 첨가량이 많을수록 NOx 저감 성능이 감소하는 것으로 나타났는데, 이는 촉매 표면상의 활성점수가 바인더에 의해 점유되어 감소된 것에 따른 것으로 판단된다. 또한 표면 코팅 상태 분석을 통하여 바인더의 첨가량이 적절히 조절 되어야 함을 알 수 있었다.

3-부티닐-p-톨루엔술포네이트를 이용한 2-에티닐피리딘의 무촉매중합을 통하여 이온성 전도성 고분자를 합성하였다. 합성 고분자의 분자구조는 IR, NMR, UV-visible 분광분석기로 확인하였다. 공액구조 주사슬 고분자의 특징적인 π → π* 전이에 기인하는 약하면서도 완만한 흡수 피크를 800 nm까지 보여 주었다. 합성한 고분자의 전기화학적 특성과 전기광학 특성을 측정하고 분석하였다. 이 고분자는 도핑과 탈도핑 사이에서 매우 안정한 비가역 전기화학적 거동을 보였다.

The diesel engine generate many pollutants such as PM(Particulate matter) and NOx(Nitrogen oxide). So the SCR(Selective catalytic reduction) must be required to meet the emission standard. The SCR catalyst market is growing rapidly, and the automobile markets using alternative energy sources are growing rapidly. This study deals with optimization of the calcination process the manufacturing process of SCR catalyst to be competitive. The calcination process is a bottleneck and it is required to optimize productivity and accept to be safety, But we cannot trade off anything in terms of safety. We applied DOE(Design of experiments) among many research methods performed in various fields. In order to achieve quality and productivity optimization. The dependent variables in the DOE were selected as NO Conversion(%). The independent variables were selected as the calcination temperature, soaking time and fan speed RPM. the CCD(Central composite designs) constructs response surface using the data onto experience and finds optimum levels within the fitted response surfaces. Our tests are our stability guarantee and efficient together with operation.

Transition metal oxide is widely used as a water electrolysis catalyst to substitute for a noble metal catalyst such as IrO2 and RuO2. In this study, the sol-gel method is used to synthesize the CuxCo3-xO4 catalyst for the oxygen evolution reaction (OER),. The CuxCo3-xO4 is synthesized at various calcination temperatures from 250 ℃ to 400 ℃ for 4 h. The CuxCo3- xO4 synthesized at 300 ℃ has a perfect spinel structure without residues of the precursor and secondary phases, such as CuO. The particle size of CuxCo3-xO4 increases with an increase in calcination temperature. Amongst all the samples studied, CuxCo3- xO4, which is synthesized at 300?, has the highest activity for the OER. Its onset potential for the OER is 370 mV and the overpotential at 10 mA/cm2 is 438 mV. The tafel slope of CuxCo3-xO4 synthesized at 300 ℃ has a low value of 58 mV/dec. These results are mainly explained by the increase in the available active surface area of the CuxCo3-xO4 catalyst.

This study deals with optimization of the calcination process the manufacturing process of SCR catalyst to be competitive. The calcination process is a bottleneck and it is required to optimize productivity and quality. We applied DOE(Design of experiments) among many research methods performed in various fields. In order to achieve quality and productivity optimization. The dependent variables in the DOE were selected as NO Conversion (%). The independent variables were selected as the calcination temperature, soaking time and fan speed RPM. The CCD(Central composite designs) constructs response surface using the data onto experience and finds optimum levels within the fitted response surfaces.

Water electrolysis is a representative electrochemical process to generate hydrogen gas together with oxygen gas by applying electric power. Perfluorinated sulfonic acid (PFSA) ionomers have been widely used as electrode binder materials, in addition to polymer electrolyte membrane materials for water electrolysis to generate hydrogen and oxygen gases with a high purity simultaneously. PFSA binder materials act as physical supports for inorganic catalyst materials in both electrodes. The binder materials play role in transporting protons for hydrogen gas and oxygen gas evolution reaction in the cathode and the anode, respectively. In this study, PFSA ionomers with different chemical architectures and equivalent weights were used as binder materials for water electrolysis. The structure property performance relationship was disclosed.