scholarly journals Improved H2 utilization by Pd doping in cobalt catalysts for reductive amination of polypropylene glycol

RSC Advances ◽  
2020 ◽  
Vol 10 (73) ◽  
pp. 45159-45169
Author(s):  
Kyungjun Kim ◽  
Dong Woo Kang ◽  
Youngheon Choi ◽  
Wanggyu Kim ◽  
Hyunjoo Lee ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Reductive Amination ◽  
Cobalt Catalysts ◽  
Cobalt Metal ◽  
Polypropylene Glycol ◽  
Hydrogen Dissociation ◽  
Pd Doping ◽  
P Addition

Addition of Pd into Co helped remarkably to reduce cobalt oxide and nitride to cobalt metal by enhanced hydrogen dissociation and desorption.

scholarly journals Microbacterium sp. MRS-1, a potential bacterium for cobalt reduction and synthesis of less/non-toxic cobalt oxide nanoparticles (Co3O4)

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Sathyavathi Sundararaju ◽  
Manjula Arumugam ◽  
Prakash Bhuyar
Keyword(s):  
Heavy Metal ◽  
Cobalt Oxide ◽  
Metal Oxide Nanoparticles ◽  
Industrial Effluent ◽  
Industrial Applications ◽  
Resistant Bacterium ◽  
Oxide Nanoparticles ◽  
Cobalt Metal ◽  
Cobalt Oxide Nanoparticles ◽  
Heavy Metal Resistant

Abstract Background Detoxification of heavy metal pollutants in wastewater has become a serious problem to surrounding environment. This research was conducted to utilize a potential heavy metal-resistant bacterium for the remediation of cobalt metal and simultaneous synthesis of cobalt oxide nanoparticles in the form of powder for various industrial applications. Metal oxide nanoparticles have great applications in electrochemical devices such as supercapacitors, biosensors, and batteries. Method A heavy metal-resistant bacterium Microbacterium sp. MRS-1 isolated from electroplating industrial effluent reduced cobalt ions from an initial concentration of 200 mg/L to 26 mg/L were analyzed by atomic absorption spectroscopy. Instrumental analysis of bacterially synthesized Co3O4 has been characterized. Cytotoxicity of synthesized nanoparticles was assessed by MTT assay. Results Microbacterium sp. MRS-1 isolated from electroplating industrial effluent was found to be suitable for cobalt oxide nanoparticles as it showed tolerance towards high concentration of metal. The nutrient broth containing metal solution and Microbacterium sp. MRS-1 showed color change from light pink to dark pink indicated the formation of extracellular nanoparticles. It also converted soluble cobalt salts into less soluble cobalt oxide nanoparticles outside the cell which allows easy recovery of nanoparticles without the destruction of cells and simultaneous detoxification of toxic metal ions. Electron microscopic imaging verified that nanoparticles were predominantly surrounding the bacterial cells and SEM imaging revealed that the produced particles were in the range of 10–100 nm in size. XRD spectrum exhibited 2θ values were corresponding to cubic face-centered cobalt oxide (Co3O4) nanoparticles. Conclusion The present study investigated new prospective for eco-friendly detoxification of toxic heavy metal Co from metal-polluted sites and the production of cobalt oxide nanoparticles in powder form for clinical and other industrial applications.

Preparation and Pretreatment Effects on Co/SiO2 Catalysts for Fischer-Tropsch Synthesis

1994 ◽  
Vol 368 ◽  
Author(s):  
Kent E. Coulter ◽  
Allen G. Sault
Keyword(s):  
Surface Properties ◽  
Photoelectron Spectroscopy ◽  
Cobalt Catalysts ◽  
Volatile Components ◽  
Cobalt Metal ◽  
Nitrate Hexahydrate ◽  
Incipient Wetness Impregnation ◽  
Supported Metal Catalysts ◽  
Drying Procedures ◽  
Wide Range

ABSTRACTCatalyst drying procedures are often given little attention in the experimental section of papers on supported metal catalysts. In general, drying appears to be regarded as a method to remove water and other volatile components prior to calcining or reduction, but not as a method to affect the surface properties of the catalyst. This study uses x-ray photoelectron spectroscopy (XPS) to examine the surface properties of silica supported cobalt catalysts, prepared using incipient wetness impregnation of cobalt nitrate hexahydrate, and finds a wide range of cobalt distributions, extent of nitrate decomposition, and reducibility for various drying procedures. After UHV annealing and subsequent reduction, the final cobalt surface properties are found to depend on the length of heating and the environment during the drying process. Maximum cobalt metal surface area is obtained for samples exposed to limited amounts of air and dried under conditions where gas phase species generated during the precursor decomposition are rapidly removed from the surface of the sample.

Reductive amination of polypropylene glycol using Ni-CeO2@Al2O3 with high activity, selectivity and stability

2019 ◽  
Vol 127 ◽  
pp. 15-19 ◽  
Author(s):  
Hung-Yen Chang ◽  
Guan-Hung Lai ◽  
Chih-Yuan Lin ◽  
Chun-Yu Lee ◽  
Chih-Cheng Chia ◽  
...  
Keyword(s):  
High Activity ◽  
Reductive Amination ◽  
Polypropylene Glycol

scholarly journals Promoted cobalt oxide catalyst on the metallic structured reactor filling for VOC combustion as an alternative to noble metal catalysts

2007 ◽  
Vol 9 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Joanna Łojewska ◽  
Andrzej Kołodziej ◽  
Jerzy Żak
Keyword(s):  
Cobalt Oxide ◽  
Noble Metal ◽  
Oxide Catalyst ◽  
Supported Catalyst ◽  
Metal Catalysts ◽  
Catalyst Design ◽  
Cobalt Catalysts ◽  
Noble Metal Catalysts ◽  
Voc Combustion ◽  
Structured Reactor

Promoted cobalt oxide catalyst on the metallic structured reactor filling for VOC combustion as an alternative to noble metal catalysts VOC combustion is a demanding process for both the reactor and the catalyst design. As we have proved in recent papers the diffusional limitation of reaction rate that occurs during combustion may be overcome by designing the metallic microstructures used as reactor internals. Their application on an industrial scale depends on the development of an efficient method of catalyst layering on metallic supports and the optimisation of a fine catalyst structure which would not change the elaborated microstructure geometry. In this study we propose the Langmuir-Blodgett (LB) film method to deposit various metals (Al, Co) in the form of catalyst organic precursors. The film forming abilities of the precursors were checked by surface pressure measurements upon film compression, Brewster Angle Microscopy and by the monolayers stability measurements. The amount of the deposited materials was controlled by the LB parameters and verified by the TG measurements. The catalyst obtained in this way were characterized at various stages of the preparation by SEM/XFS, XPS, AFM and RM methods and tested in n-hexane combustion. Oxidation of the Al washcoat precursor led to the formation of γ-Al2O3 improving the properties of the Al2O3 layer (α phase) developed on the pre-calcined CrAl carrier. Oxidation of cobalt stearate deposited on the CrAl produced dispersed Co3O4 spinel. The cobalt catalysts were active in combustion showing resistance to sintering. Compared to standard Pt supported catalyst it demonstrated twice as low activation energy (50 kJ/mol).

scholarly journals DEVELOPMENT AND INDUSTRIAL APPROBATION OF TECHNOLOGIES OF COBALT CATALYSTS FOR SYNTHESIS OF LONG CHAIN HYDROCARBONS FROM SYNTHESIS GAS

2018 ◽  
Vol 61 (9-10) ◽  
pp. 53-58
Author(s):  
Alexander P. Savostyanov ◽  
Roman E. Yakovenko ◽  
Grigory B. Narochny ◽  
Vera G. Bakun ◽  
Alexander A. Merkin
Keyword(s):  
Aluminum Oxide ◽  
Synthesis Gas ◽  
Close Packing ◽  
Cobalt Catalysts ◽  
Catalyst Loading ◽  
Cobalt Metal ◽  
Active Components ◽  
Technological Parameters ◽  
Catalytic Systems ◽  
Long Chain

The compositions, methods of preparation and specific technological parameters of the production processes of cobalt catalysts for the synthesis of long chain hydrocarbons from synthesis gas were justified. To obtain C35+ selective catalysts by coprecipitation of active components, the carrier must provide a polydisperse distribution of the pore volume along the radii. This is achieved by hydrothermal treatment of the aluminosilicate carrier. To increase the strength of catalysts, it is possible to incorporate natural bentonites and diatomite of Roctov region deposits into the composition of coprecipitated catalysts. Effective catalytic systems are impregnated catalysts on Al2O3 and SiO2 supports with aluminum oxide promotion. The insertion of 5% - Al2O3 of cobalt metal mass allows to form crystallites of Co-CoO system with a size of 8 nm on the SiO2 surface, which provides high activity and selectivity for ceresin. Aluminum oxide is stabilized with Co3O4 in a structure with a high degree of ordering, without hindering its reduction, with the formation of cobalt predominantly with the crystalline structure of hexagonal close packing. Catalyst technologies are implemented in industry. The catalysts underwent continuous continuous testing (1000 h) in laboratory and industrial conditions, showed high stability of operation. During the entire operation, the yield of C5+ hydrocarbons was 159-171 g/Nm3 based on the processed synthesis gas. The long-chain hydrocarbons C35+ (ceresin) obtained are of high quality: the dropping point was 114-116 °C (37-40% ceresin content). Operation during the year of two industrial reactors at the Novocherkassk plant of synthetic products with a total volume of catalyst loading of 18 m3 confirmed the results of laboratory tests. For citation: Savostyanov A.P., Yakovenko R.E., Narochny G.B., Bakun V.G., Merkin A.A. Development and industrial approbation of technologies of cobalt catalysts for synthesis of long chain hydrocarbons from synthesis gas. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 53-58

Front Cover: Expedient Synthesis of N -Methyl- and N -Alkylamines by Reductive Amination using Reusable Cobalt Oxide Nanoparticles (ChemCatChem 6/2018)

ChemCatChem ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 1202-1202
Author(s):  
Thirusangumurugan Senthamarai ◽  
Kathiravan Murugesan ◽  
Kishore Natte ◽  
Narayana V. Kalevaru ◽  
Helfried Neumann ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Reductive Amination ◽  
Oxide Nanoparticles ◽  
Front Cover ◽  
Cobalt Oxide Nanoparticles

Expedient Synthesis of N -Methyl- and N -Alkylamines by Reductive Amination using Reusable Cobalt Oxide Nanoparticles

ChemCatChem ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 1235-1240 ◽  
Author(s):  
Thirusangumurugan Senthamarai ◽  
Kathiravan Murugesan ◽  
Kishore Natte ◽  
Narayana V. Kalevaru ◽  
Helfried Neumann ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Reductive Amination ◽  
Oxide Nanoparticles ◽  
Cobalt Oxide Nanoparticles
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