scholarly journals THE STEREOCHEMISTRY EFFECT OF EUGENOL, CIS-ISOEUGENOL AND TRANS-ISOEUGENOL ON THEIR CATALYTIC HIDROGENATION

2010 ◽  
Vol 4 (2) ◽  
pp. 99-105
Author(s):  
M. Muchalal
Keyword(s):  
Mass Spectrum ◽  
Catalytic Hydrogenation ◽  
Computer Modelling ◽  
Hydrogen Gas ◽  
Hydrogenation Product ◽  
Semiempirical Methods ◽  
Calcination Process ◽  
Gas Atmosphere ◽  
Catalytic Reactivity ◽  
Al2o3 Catalyst

The stereochemistry effect of eugenol, cis-isoeugenol and trans-isoeugenol on their catalytic hydrogenation by Ni/g-Al2O3 catalyst was investigated. In this investigation, the catalyst is prepared by impregnation of Nickel into solid of γ-Al2O3 in methanol as a solvent. The calcination process, which is followed by reduction, is performed on Muchalal reactor at 400 oC. After that, the catalytic hydrogenation is carried out under hydrogen gas atmosphere by mixing 10 mL sample and 0.5 g Ni/g-Al2O3 catalyst at 200 oC for 3 hours. The stereochemistry effect of reactants is evaluated by computer modelling using PM3 semiempirical methods. The mass spectrum of catalytic hydrogenation product from those compounds shows a molecular ion at m/z 164, which proves the existence of 2 -methoxy-4-propylphenol. The eugenol gives the highest conversion (99%), followed by cis-isoeugenol (81%) and trans-isoeugenol (67%). It was found that there is a correlation between the stereochemistry of those compounds and catalytic reactivity.   Keywords: stereochemistry effects, 2-methoxy-4-propylphenol

Effects of the preparation method on the performance of the Cu/ZnO/Al2O3 catalyst for the manufacture of l-phenylalaninol with high ee selectivity from l-phenylalanine methyl ester

2014 ◽  
Vol 4 (4) ◽  
pp. 1132-1143 ◽  
Author(s):  
Zhangping Shi ◽  
Xiuzhen Xiao ◽  
Dongsen Mao ◽  
Guanzhong Lu
Keyword(s):  
Methyl Ester ◽  
Catalytic Hydrogenation ◽  
Preparation Method ◽  
Phenylalanine Methyl Ester ◽  
Al2o3 Catalyst

Efficient catalytic hydrogenation of l-phenylalanine methyl ester to l-phenylalaninol over the Cu/ZnO/Al2O3 catalyst with ~100% ee selectivity.

Infrared Spectroscopy of Molten LiCl−KCl under Hydrogen Gas Atmosphere

2004 ◽  
Vol 108 (21) ◽  
pp. 4567-4569 ◽  
Author(s):  
Hironori Nakajima ◽  
Toshiyuki Nohira ◽  
Yasuhiko Ito
Keyword(s):  
Infrared Spectroscopy ◽  
Hydrogen Gas ◽  
Gas Atmosphere

scholarly journals Stacking Fault Energy in Relation to Hydrogen Environment Embrittlement of Metastable Austenitic Stainless CrNi-Steels

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1170
Author(s):  
Robert Fussik ◽  
Gero Egels ◽  
Werner Theisen ◽  
Sebastian Weber
Keyword(s):  
Phase Transformation ◽  
Intermediate Stage ◽  
Tensile Tests ◽  
Stacking Fault ◽  
Hydrogen Gas ◽  
Stacking Fault Energy ◽  
Austenitic Steels ◽  
Aisi 304L ◽  
Hydrogen Environment ◽  
Gas Atmosphere

Metastable austenitic steels react to plastic deformation with a thermally and/or mechanically induced martensitic phase transformation. The martensitic transformation to α’-martensite can take place directly or indirectly via the intermediate stage of ε-martensite from the single-phase austenite. This effect is influenced by the stacking fault energy (SFE) of austenitic steels. An SFE < 20 mJ/m2 is known to promote indirect conversion, while an SFE > 20 mJ/m2 promotes the direct conversion of austenite into α’-martensite. This relationship has thus far not been considered in relation to the hydrogen environment embrittlement (HEE) of metastable austenitic CrNi steels. To gain new insights into HEE under consideration of the SFE and martensite formation of metastable CrNi steels, tensile tests were carried out in this study at room temperature in an air environment and in a hydrogen gas atmosphere with a pressure of p = 10 MPa. These tests were conducted on a conventionally produced alloy AISI 304L and a laboratory-scale modification of this alloy. In terms of metal physics, the steels under consideration differed in the value of the experimentally determined SFE. The SFE of the AISI 304L was 22.7 ± 0.8 mJ/m2 and the SFE of the 304 mod alloy was 18.7 ± 0.4 mJ/m2. The tensile specimens tested in air revealed a direct γàα’ conversion for AISI 304L and an indirect γàεàα’ conversion for 304mod. From the results it could be deduced that the indirect phase transformation is responsible for a significant increase in the content of deformation-induced α’-martensite due to a reduction of the SFE value below 20 mJ/m2 in hydrogen gas atmosphere.

scholarly journals Catalytic hydrogenation of straight vegetable oil using NiMo/ Al2O3 catalyst for biodiesel production

2018 ◽  
Vol 67 ◽  
pp. 02045
Author(s):  
SD Sumbogo Murti ◽  
J. Prasetyo ◽  
G.W. Murti ◽  
Z. D. Hastuti ◽  
F. M. Yanti
Keyword(s):  
Vegetable Oil ◽  
Catalytic Hydrogenation ◽  
Cooling System ◽  
Cetane Number ◽  
Chemical Properties ◽  
Raw Material ◽  
Biodiesel Production ◽  
Operation Condition ◽  
Straight Vegetable Oil ◽  
Al2o3 Catalyst

The attractiveness of biodiesel as an alternative fuel compared to fossil fuels because it has many advantages such as the availability of abundant raw materials, more environmentally friendly, high combustion efficiency, low sulphur content, high cetane number and biodegradability. Making biodiesel from straight vegetable oil (VGO) has been done through the catalytic hydrogenation process. A VGO of callophylum inophyllum oil was treated via degumming and neutralisation to remove all impurities before hydroprocessing. Hydroprocessing was carried out in a 500ml autoclave at 30 – 50 MPa of initial hydrogen pressure, 300 – 400oC of reaction temperature and equipped with stirrer and cooling system. NiMo/Al2O3 catalyst was activated with CS2 mixture at 370oC prior to the reaction. Some physical and chemical properties of the catalytic hydroprocessing product have been investigated in accordance to ASTM standard. The measurement result of product varies according to the operation condition. The result showed that callophyllum inophyllum oil can be used as raw material for biodiesel production over NiMo/Al2O3. Sulfided NiMo/Al2O3 catalysts are preferred due to high diesel yield.

Buried Metal Deposition on Gallium Arsenide by Laser-Induced Thermochemical Reaction

1987 ◽  
Vol 101 ◽  
Author(s):  
Jun Tokuda ◽  
Mikio Takai ◽  
Kenji Gamo ◽  
Susumu Namba
Keyword(s):  
Gallium Arsenide ◽  
Tin Oxide ◽  
Tin Dioxide ◽  
Density Ratio ◽  
Hydrogen Gas ◽  
Outer Side ◽  
Gas Atmosphere ◽  
Oxide Deposition ◽  
Ion Laser ◽  
Deposited Film

ABSTRACTTin oxide deposition was performed by focused argon ion laser irradiation in a tin tetrachloride gas atmosphere. Etching of gallium arsenide and tin oxide deposition were observed in a single scan of a laser beam under specific conditions. The center of the irradiated area was etched and then covered with deposit. Density ratio of 0/Sn obtained from the deposit by AES measurements was about 1.4 - 1.6. Additional hydrogen gas in ambient SnCl4 gas reduced both tin oxide deposition and gallium arsenide etching. Deposition, at first, occurred at the outer side of the irradiated area and gallium arsenide etching occurred at the center of it. The amount of deposit depends on beam dwell time. Additional oxygen in ambient SnCl4 gas improved deposited film quality: the deposited film with additional oxygen proved to be tin dioxide, which is an conductor.

BN/NiO nanocomposites: Structural, defect chemistry and electrical properties in hydrogen gas atmosphere

2020 ◽  
Vol 46 (16) ◽  
pp. 26233-26237
Author(s):  
Kulwinder Singh ◽  
Manjot Kaur ◽  
Ishant Chauhan ◽  
Amit Awasthi ◽  
Manjeet Kumar ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Structural Defect ◽  
Defect Chemistry ◽  
Hydrogen Gas ◽  
Gas Atmosphere

scholarly journals Production of Fe-C Alloys through Reduction and Sintering of Cementite Powders in Hydrogen Gas Atmosphere

2007 ◽  
Vol 93 (3) ◽  
pp. 228-233 ◽  
Author(s):  
Koichi NAKASHIMA ◽  
Nobuaki OUCHIDA ◽  
Makoto EGASHIRA ◽  
Toshihiro TSUCHIYAMA ◽  
Setsuo TAKAKI
Keyword(s):  
Hydrogen Gas ◽  
Gas Atmosphere

Theoretical Analysis of Porosity in an Ordered Porous Copper Fabricated by Continuous Unidirectional Solidification

2018 ◽  
Vol 933 ◽  
pp. 136-141
Author(s):  
Rong Cao ◽  
Qing Lin Jin
Keyword(s):  
High Pressure ◽  
Theoretical Model ◽  
Theoretical Analysis ◽  
Processing Parameters ◽  
Unidirectional Solidification ◽  
Hydrogen Gas ◽  
Porous Copper ◽  
Gas Atmosphere ◽  
Ordered Porous ◽  
Good Agreement

Ordered porous copper with elongated pores has been fabricated by a continuous unidirectional solidification method in a hydrogen gas atmosphere with high pressure. The porosity of the ordered porous copper is significantly affected by the pressure of hydrogen. A theoretical model is developed to get the relation between the porosity and the processing parameters. The calculated values are in good agreement with the experimental results. Key words: Unidirectional solidification; Ordered porous copper; Porosity; Modeling.

Hydrogen Passivation of Er and Si Nanocrystallites in Er-doped SiO2 - Increase in Photoluminescence-

2004 ◽  
Vol 832 ◽  
Author(s):  
N. Fukata ◽  
C. Li ◽  
H. Uematsu ◽  
T. Arai ◽  
T. Makimura ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Signal Intensity ◽  
Hydrogen Gas ◽  
Hydrogen Passivation ◽  
Si Substrate ◽  
Gas Atmosphere ◽  
Oxygen Gas ◽  
Pl Intensity ◽  
Er Doped ◽  
Si Nanocrystallites

ABSTRACTHydrogen passivation effect on the enhancement of photoluminescence (PL) of Er ions in SiO2 films contained Si nanocrystallites (nc-Si) has been investigated. Er-doped SiO2 films were fabricated by laser ablation of Er-deposited Si substrate in oxygen gas atmosphere. The PL intensity of Er ions and nc-Si were increased by hydrogen gas treatments, while ESR signal intensity of residual defects located at the interfaces between nc-Si and SiO2 was decreased. These results indicate that hydrogen passivation of residual defects is useful for the enhancement of the Er PL.

Production of CO-rich hydrogen gas from glycerol dry reforming over La-promoted Ni/Al2O3 catalyst

2014 ◽  
Vol 39 (13) ◽  
pp. 6927-6936 ◽  
Author(s):  
Kah Weng Siew ◽  
Hua Chyn Lee ◽  
Jolius Gimbun ◽  
Chin Kui Cheng
Keyword(s):  
Dry Reforming ◽  
Hydrogen Gas ◽  
Al2o3 Catalyst
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