The effect of Cu/Zn molar ratio on CO2 hydrogenation over Cu/ZnO/ZrO2/Al2O3 catalyst

2014 ◽  
Author(s):  
Salina Shaharun ◽  
Maizatul S. Shaharun ◽  
Dasmawati Mohamad ◽  
Mohd F. Taha
Keyword(s):  
Co2 Hydrogenation ◽  
Molar Ratio ◽  
Al2o3 Catalyst

Dimethyldisulphide Hydrodesulphurization on NiCoMo / Al2O3 Catalyst

2017 ◽  
Vol 68 (7) ◽  
pp. 1496-1500
Author(s):  
Rami Doukeh ◽  
Mihaela Bombos ◽  
Ancuta Trifoi ◽  
Minodora Pasare ◽  
Ionut Banu ◽  
...  
Keyword(s):  
Good Accuracy ◽  
Fixed Bed ◽  
Continuous System ◽  
Space Velocity ◽  
Molar Ratio ◽  
Catalytic Reactor ◽  
Liquid Hourly Space Velocity ◽  
Hydrodesulfurization Process ◽  
Al2o3 Catalyst ◽  
Simplified Kinetic Model

Hydrodesulphurization of dimethyldisulphide was performed on Ni-Co-Mo /�-Al2O3 catalyst. The catalyst was characterized by determining the adsorption isotherms, the pore size distribution and the acid strength. Experiments were carried out on a laboratory echipament in continuous system using a fixed bed catalytic reactor at 50-100�C, pressure from 10 barr to 50 barr, the liquid hourly space velocity from 1h-1 to 4h-1 and the molar ratio H2 / dimethyldisulphide 60/1. A simplified kinetic model based on the Langmuir�Hinshelwood theory, for the dimethyldisulphide hydrodesulfurization process of dimethyldisulphide has been proposed. The results show the good accuracy of the model.

Vapor-phase oxidation of propylene glycol-methanol mixture to methyl lactate on CeO2/Al2O3 catalyst

2021 ◽  
pp. 92-97
Author(s):  
M.E. Sharanda ◽  
◽  
A.M. Mylin ◽  
O.Yu. Zinchenko ◽  
V.V. Brei ◽  
...  
Keyword(s):  
Propylene Glycol ◽  
Vapor Phase ◽  
Flow Reactor ◽  
Aldol Condensation ◽  
Ethyl Lactate ◽  
Molar Ratio ◽  
Methyl Lactate ◽  
Reactor Inlet ◽  
Phase Oxidation ◽  
Al2o3 Catalyst

The vapor-phase oxidation of mixtures of propylene glycol with methanol and ethanol to methyl and ethyl lactate, respectively, on supported CeO2/Al2O3 catalyst with 10 wt.% CeO2 content was studied. The steel flow reactor with a fixed catalyst bed (4 cm3) was used. 20 wt.% solution of propylene glycol in alcohol was fed to the reactor inlet by Waters 950 pump at LHSV= 0.5-0.8 h-1. Reaction temperature and pressure were varied in the interval of 190-250 0C and 1.3-1.8 bars respectively. Compressed air was given to the reactor inlet at the molar ratio of propylene glycol/O2 = 1. The reaction products were analyzed using gas chromatography (Agilent 7820A) and 3C NMR (Bruker Avance 400) methods. Studied oxidation of propylene glycol in the presence of methanol describes by total reaction CH3CHOHCH2OH +O2 + СН3OH = CH3CHOHCOOСН3 +2H2O At first, hydroxyacetone is formed that is further oxidized to pyruvic aldehyde, which attaches alcohol to form hemiacetal. Then, hemiacetal of methyl glyoxal rearranges into methyl lactate by Cannizzaro. At 220 0C and load on a catalyst of < 2 mmol PG/gcat/h, the selectivity towards methyl lactate reaches 70 wt.% at 100 % propylene glycol conversion. The main by-products are formed as the result of acetaldehyde transformation. Acetaldehyde could be formed at hydroxyacetone aldol decondensation. In the presence of ethanol, the formation of a significant amount of acetaldehyde and its aldol condensation products as well as the formation of diethoxyethane are observed. Therefore, ethyl lactate selectivity at 100 % propylene glycol conversion does not exceed 45 %. Supported CeO2/SiO2 contact was tested in this oxidation reaction also. However, CeO2/SiO2 provides the low, up to 25%, selectivity towards methyl lactate at full propylene glycol conversion. It was shown that at the same conditions methyl lactate is formed with higher selectivity then ethyl lactate. The high methyl lactate yield up to 70 wt.% could be obtained via vapor-phase oxidation of 20% mixture of propylene glycol with methanol by air oxygen on supported CeO2/Al2O3 catalyst at 210 - 220°С and at time contact of 3-4 seconds.

scholarly journals Structure and Catalytic Behavior of Alumina Supported Bimetallic Au-Rh Nanoparticles in the Reduction of NO by CO

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 937 ◽  
Author(s):  
Wang ◽  
Wang ◽  
Maeda ◽  
Baiker
Keyword(s):  
Bimetallic Catalyst ◽  
Metal Salt ◽  
Surface Region ◽  
Molar Ratio ◽  
Reduction Of No ◽  
Surface Population ◽  
Adsorption Of Co ◽  
Enhanced Adsorption ◽  
Co Reduction ◽  
Al2o3 Catalyst

Alumina-supported bimetallic AuRh catalysts, as well as monometallic reference catalysts, were examined with regard to their structural and catalytic properties in the reduction of NO by CO. Depending on the molar ratio of Au:Rh, the nanoparticles prepared by borohydride co-reduction of corresponding metal salt solutions had a size of 3.5–6.7 nm. The particles consisted of well-dispersed noble metal atoms with some enrichment of Rh in their surface region. NO conversion of AuRh/Al2O3 shifted to lower temperatures with increasing Rh content, reaching highest activity and highest N2 selectivity for the monometallic Rh/Al2O3 catalyst. This behavior is attributed to the enhanced adsorption of CO on the bimetallic catalyst resulting in unfavorable cationic Rh clusters Rh+-(CO)2. Doping with ceria of AuRh/Al2O3 and Rh/Al2O3 catalysts increased the surface population of metallic Rh sites, which are considered most active for the reduction of NO by CO and enhancement of the formation of intermediate isocyanate (-NCO) surface species and their reaction with NO to form N2 and CO2.

scholarly journals Visible light-enhanced photothermal CO2 hydrogenation over Pt/Al2O3 catalyst

2020 ◽  
Vol 41 (2) ◽  
pp. 286-293 ◽  
Author(s):  
Ziyan Zhao ◽  
Dmitry E. Doronkin ◽  
Yinghao Ye ◽  
Jan-Dierk Grunwaldt ◽  
Zeai Huang ◽  
...  
Keyword(s):  
Visible Light ◽  
Co2 Hydrogenation ◽  
Al2o3 Catalyst

scholarly journals Synthesis and characterization of Cu-X/γ-Al2O3 catalyst by intermittent microwave irradiation for hydrogen generation from dimethyl ether steam reforming

2018 ◽  
Vol 24 (2) ◽  
pp. 169-178
Author(s):  
Shilin Huang ◽  
Juan Li ◽  
Chang-Feng Yan ◽  
Zhida Wang ◽  
Changqing Guo ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Dimethyl Ether ◽  
Steam Reforming ◽  
Hydrogen Generation ◽  
Molar Ratio ◽  
Hydrogen Yield ◽  
Methanol Reforming ◽  
Dimethyl Ether Conversion ◽  
Shift Reaction ◽  
Al2o3 Catalyst

A series of Cu-X/?-Al2O3 (X = Fe, Co, Ni) catalysts were synthesized by a rapid intermittent microwave irradiation method for hydrogen generation from dimethyl ether steam reforming. Different parameters, such as the promoters of X (X = Fe, Co, Ni), microwave irradiation procedure and the ratio of metal to ?-Al2O3, were investigated. The results show that 2Cu-Fe/72?-Al2O3 has the best performance, for which the agglomeration is prevented, CuO is well dispersed and the catalytic activity is improved. Promoter iron oxide in 2Cu-Fe/9?-Al2O3 facilitates the watergas shift reaction, which lead to an increase in the conversion of CO to CO2 and hydrogen yield. Particularly, the 2Cu-Fe/72?-Al2O3 catalyst, with the best molar ratio of metal to ?-Al2O3, shows a dimethyl ether conversion of >99% and a hydrogen yield of >98% and produces the lowest CO content of 1.4%, indicating that the synergism between dimethyl ether hydrolysis and methanol reforming requires an appropriate balance between the metallic Cu-Fe and the acid ?-Al2O3. The intermittent microwave irradiation technique provides a simple but effective method of the Cu-Fe/?-Al2O3 synthesis with a good catalyst performance for the dimethyl ether steam reforming.

Growth of carbon nanofibers synthesized from CO2 hydrogenation on a K/Ni/Al2O3 catalyst

2009 ◽  
Vol 11 (3) ◽  
pp. 220-224 ◽  
Author(s):  
Ching-Shiun Chen ◽  
Jarrn-Horng Lin ◽  
Jia-Huang Wu ◽  
Cheng-Yu Chiang
Keyword(s):  
Carbon Nanofibers ◽  
Co2 Hydrogenation ◽  
Al2o3 Catalyst

scholarly journals Optimizing Pd:Zn molar ratio in PdZn/CeO2 for CO2 hydrogenation to methanol

2019 ◽  
Vol 584 ◽  
pp. 117185 ◽  
Author(s):  
Opeyemi A. Ojelade ◽  
Sharif F. Zaman ◽  
Muhammad A. Daous ◽  
Abdulrahim A. Al-Zahrani ◽  
Ali S. Malik ◽  
...  
Keyword(s):  
Co2 Hydrogenation ◽  
Molar Ratio
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