http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Cong-Ming Tang (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
Cong-Ming Tang,Xin-Li Li,Gong-Ying Wang 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.12
A non-petroleum approach for the catalytic synthesis of methyl acrylate via methoxycarbonylation of acetylene with carbon monoxide and methanol as nucleophilic reagent has been studied under various conditions. Pd(OAc)2/2-PyPPh2/p-tsa was found to be a highly efficient catalytic system. The types of phosphorus ligands and their concentration was a determinative factor for catalytic activity. Mono-dentate phosphorus ligand such as triphenylphosphine has no activity while 2-(diphenylphosphino)pyridine with a mixed N-P bidentate structure has an excellent activity. Catalytic performance of acids depends on their acidic strength and coordinative property. Among all acidic promoters, p-toluenesulfonic acid displayed an excellent performance. Other parameters such as solvent polarity and initial pressure of carbon monoxide have also important influences on the hydroesterification of acetylene. It is beneficial for the reaction that the solvents have a high polarity. At low pressure of carbon monoxide, to high active palladium catalyst, the reaction easily proceeded. However, at high pressure of carbon monoxide, acetylene will transfer from solution to gas phase,resulting in lower conversion of acetylene. In addition, due to steric hindrance of alcohols, methanol has a highest activity in hydroesterification of acetylene in low carbon alcohols. Under the optimal reaction conditions, 99.5% of acetylene conversion and 99.7% of selectivity toward methyl acrylate as well as 2,502 h−1 TOF were achieved.
-
Separative capability of γ-Al2O3 porous ceramic membrane modified by ZIF-8
Cong-Ming Tang,Xin-Li Li 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.5
Several precursors such as zinc nitrite, zinc chloride, zinc acetate and zinc sulfate were used to synthesize ZIF-8. These zeolitic imidazolate frameworks synthesized from different zinc precursors under different reaction conditions were characterized by XRD, SEM and FTIR. The synthesis of ZIF-8 was not sensitive to zinc precursor and reaction parameter. Subsequently, we used ZIF-8 to modify the γ-Al2O3 porous ceramic membrane, expecting improvement of separation performance in the γ-Al2O3 porous ceramic membrane. The experimental results indicated that the permselectivity of hydrogen/nitrogen was enhanced in the γ-Al2O3 porous ceramic membrane modified with ZIF-8,although the gas permeance through the modified membrane slightly decreased. In addition, the modified γ-Al2O3 porous ceramic membrane was used to separate the binary systems containing ethanol-water and acrylic acid-water. The separation factor of ethanol to water is 3.1, while it is 2.6 as for acrylic acid-water. Furthermore, the permeance in the former is about five times than that of the latter.
-
Sustainable production of acetaldehyde from lactic acid over the carbon catalysts
Cong-Ming Tang,Jiansheng Peng,Xin-Li Li,Zhanjie Zhai,Hejun Gao,Wei Bai,Ning Jiang,Yunwen Liao 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.1
The synthesis of acetaldehyde from lactic acid over the carbon material catalysts was investigated. The carbon materials were characterized by scanning electron microscopy for morphologic features, by X-ray diffraction for crystal phases, by Fourier transform infrared spectroscopy for functional group structures, by N2 sorption for specific surface area and by ammonia temperature-programed desorption for acidity, respectively. Among the tested carbon catalysts, mesoporous carbon displayed the most excellent catalytic performance. By acidity analysis, the medium acidity is a crucial factor for catalytic performance: more medium acidity favored the formation of acetaldehyde from lactic acid. To verify, we compared the catalytic performance of fresh activated carbon with that of the activated carbon treated by nitric acid. Similarly, the modified activated carbon also displayed better activity due to a drastic increase of medium acidity amount. However, in contrast to fresh carbon nanotube, the treated sample displayed worse activity due to decrease of medium acidity amount. The effect of reaction temperature and time on stream on the catalytic performance was also investigated. Under the optimal reaction conditions, 100% lactic acid conversion and 91.6% acetaldehyde selectivity were achieved over the mesoporous carbon catalyst.
-
SYNTHESIS AND PROPERTIES OF ONE-DIMENSIONAL ALUMINUM NITRIDE NANOSTRUCTURES
YONG-BING TANG,HONG-TAO CONG,HUI-MING CHENG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2007 NANO Vol.2 No.6
This article presents a brief review of the recent research progresses achieved in the field of one-dimensional (1D) aluminum nitride (AlN) nanostructures. It mainly covers three aspects: The first one is to introduce the synthetic strategies for several classic 1D AlN nanostructures (such as nanofibers, nanobelts, nanorods, nanowires, nanotips, etc.) including template-confined reaction, arc discharge, catalyst-assisted growth, and vapor transport and related growth methods. The second is to elaborate some special physical properties, such as field emission and photoluminescence, which associate with the uniqueness of 1D AlN nanostructures. It is revealed that aligned AlN 1D nanostructures have low turn-on and threshold voltages, high emission current and small current fluctuation, and that the photoluminescence of AlN nanobelts are different from those of conventional AlN material. The third is to briefly illustrate the potential application of these 1D AlN nanostructures in composite materials. It is found that AlN nanowire is a good reinforcement for improving the mechanical and thermal properties of metal matrix composites, which can be expected to be utilized as packaging material with high strength and low thermal expansion. Finally, we summarize the major challenges in this field. Among them, a thorough understanding of the growth mechanism of 1D AlN nanostructures is the most important issue, and more precisely controlled growth is required to obtain tailored AlN nanostructures according to device applications.
-
Gong-Ying Wang,Zhiyong Deng,Ning Jiang,Shaoying Liu,Cong-Ming Tang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.9
Water plays a crucial role in the synthesis mechanism of metal organic framework-5 (MOF-5). Synthesized MOF-5 with good phase structure and large specific surface area is largely determined by an important synthesis factor: the total water concentration of the initial synthesis solution (Ctw). An understanding of the effects of different and high Ctw on the synthesis of MOF-5 and the investigation of the maximum Ctw suitable for the synthesis of MOF-5 are important to guide the synthesis of MOF-5. Through the research of the maximum Ctw, a favorable synthetic approach was established which could realize the synthesis of MOF-5 with fine performance on CO2 adsorption and separation. The research results show that the maximum Ctw could be as high as 1,440mmol/L, and synthesized MOF- 5 still has a good phase structure and a large specific surface area of 2,136m2/g (BET). Synthesized MOF-5 by the maximum Ctw exhibits a high CO2 adsorption capacity of 2.5mmol/g and a low N2 adsorption capacity of 0.2mmol/g at 298 K and 100 kPa. More importantly, synthesized MOF-5 by the maximum Ctw exhibits a high selectivity for CO2/N2 of 18-22 at 298 K and 20-130 kPa in simulated flue gas.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
