scholarly journals Antibacterial Films of Alginate-CoNi-Coated Cellulose Paper Stabilized Co NPs for Dyes and Nitrophenol Degradation

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4122
Author(s):  
Yasir Anwar ◽  
Hani S. H. Mohammed Ali ◽  
Waseeq Ur Rehman ◽  
Hassan A. Hemeg ◽  
Shahid Ali Khan
Keyword(s):  
Catalyst Activity ◽  
Catalyst System ◽  
Weight Percent ◽  
Solid Substrate ◽  
Solid Support ◽  
Methyl Orange Dye ◽  
Catalyst Dosage ◽  
Co Nanoparticles ◽  
Nitrophenol Degradation ◽  
Cellulose Filter

The development of a solid substrate for the support and stabilization of zero-valent metal nanoparticles (NPs) is the heart of the catalyst system. In the current embodiment, we have prepared solid support comprise of alginate-coated cellulose filter paper (Alg/FP) for the synthesis and stabilization of Co nanoparticles (NPs) named as Alg/FP@Co NPs. Furthermore, Alginate polymer was blended with 1 and 2 weight percent of CoNi NPs to make Alg-CoNi1/FP and Alg-CoNi2/FP, respectively. All these stabilizing matrixes were used as dip-catalyst for the degradation of azo dyes and reduction of 4-nitrophenol (4NP). The effect of initial dye concentration, amount of NaBH4, and catalyst dosage was assessed for the degradation of Congo red (CR) dye by using Alg-CoNi2/FP@Co NPs. Results indicated that the highest kapp value (3.63 × 10−1 min−1) was exhibited by Alg-CoNi2/FP@Co NPs and lowest by Alg/FP@Co NPs against the discoloration of CR dye. Furthermore, it was concluded that Alg-CoNi2/FP@Co NPs exhibited strong catalyst activity against CR, and methyl orange dye (MO) degradation as well as 4NP reduction. Antibacterial activity of the prepared composites was also investigated and the highest l activity was shown by Alg-CoNi2/FP@Co NPs, which inhibit 2.5 cm zone of bacteria compared to other catalysts.

scholarly journals Optimal Catalyst and Cocatalyst Precontacting in Industrial Ethylene Copolymerization Processes

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Paul Aigner ◽  
Christian Paulik ◽  
Apostolos Krallis ◽  
Vasileios Kanellopoulos
Keyword(s):  
Mass Transfer ◽  
Catalyst Activity ◽  
Plug Flow ◽  
Mass Transfer Process ◽  
Catalyst System ◽  
Transfer Model ◽  
Catalyst Activation ◽  
Before And After ◽  
Natta Catalyst ◽  
Experimental Findings

In industrial-scale catalytic olefin copolymerization processes, catalyst and cocatalyst precontacting before being introduced in the polymerization reactor is of profound significance in terms of catalyst kinetics and morphology control. The precontacting process takes place under either well-mixing (e.g., static mixers) or plug-flow (e.g., pipes) conditions. The scope of this work is to study the influence of mixing on catalyst/cocatalyst precontacting for a heterogeneous Ziegler-Natta catalyst system under different polymerization conditions. Slurry ethylene homopolymerization and ethylene copolymerization experiments with 1-butene are performed in a 0.5 L reactor. In addition, the effect of several key parameters (e.g., precontacting time, and ethylene/hydrogen concentration) on catalyst activity is analyzed. Moreover, a comprehensive mass transfer model is employed to provide insight on the mass transfer process and support the experimental findings. The model is capable of assessing the external and internal mass transfer limitations during catalyst/cocatalyst precontacting process. It is shown that catalyst/cocatalyst precontacting is very important for the catalyst activation as well as for the overall catalyst kinetic behavior. The study reveals that there is an optimum precontacting time before and after which the catalyst activity decreases, while this optimum time depends on the precontacting mixing conditions.

Study on Preparation and Decontamination Properties of Hybrid-Photocatalysis Based on Graphene and TiO2

2015 ◽  
Vol 1092-1093 ◽  
pp. 988-991
Author(s):  
Zhi Ying Xu ◽  
Xin Gang Wang ◽  
Yang Bo Liu ◽  
Wei Sheng Ma ◽  
Ze Qin Mo
Keyword(s):  
Methyl Orange ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Main Phase ◽  
Light Irradiation ◽  
Optimum Ph ◽  
Methyl Orange Dye ◽  
Catalyst Dosage ◽  
Hybrid Photocatalyst

The hybrid-photocatalyst was successfully prepared by compositing graphene and TiO2 in this thesis. The properties of the hybrid-photocatalyst was stydited by XRD, SEM. The hotocatalytic activity of the hybrid-photocatalyst was evaluated by decolorization of acid yellow dye solution under visible light irradiation. The result shows that the main phase of the hybrid-photocatalyst is antase TiO2. The effects of different titanium carbon ratio, photocatalysis time, catalyst dosage and pH on the photocatalytic for acid yellow dye are discussed. Under the conditions that titanium carbon ratio 100:50, the photocatalytic time 120 min, catalyst dosing concentration 0.1g / L and the optimum pH 8, the treatment of methyl orange dye is the best.

Binary molybdenum-based catalyst for coordination polymerization of styrene

2016 ◽  
Vol 49 (5) ◽  
pp. 408-421 ◽  
Author(s):  
Jieting Geng ◽  
Youguo Shao ◽  
Feng Song ◽  
Feng Li ◽  
Jing Hua
Keyword(s):  
Molecular Weight ◽  
Catalyst Activity ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Catalyst System ◽  
Bulk Polymerization ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Coordination Polymerization ◽  
Co Catalyst

Coordination polymerization of styrene (St) using molybdenum pentachloride supported by phosphite ligand in the presence of metal organic compound was studied for the first time. The types of phosphite and co-catalysts significantly affected the catalytic activity of the molybdenum (V) (Mo(V)) active center and the number-average molecular weight ( Mn) of the resultant polymer. Among the examined catalysts, tri(nonylphenyl)phosphite (TNPP) ligand and AlOPhCH3( i-Bu)2 as co-catalyst provided the polymer with highest yield (up to 87.1%), metallocene as co-catalyst provided the polymer with highest Mn (up to 5.32 × 105). The effect of [P]/[Mo] molar ratio on catalyst activity of the polymerization was discussed and the structures of Mo·TNPP complexes were preliminarily studied by infrared (IR) and ultraviolet spectroscopies. Besides, the polystyrene (PS) samples synthesized through bulk polymerization and solution polymerization were characterized by gel permeation chromatography, IR, carbon 13 nuclear magnetic resonance, and differential scanning calorimetry, respectively, and the results indicated both of the PS had high molecular weight (approximately 105) and atactic structure. All these results demonstrated that Mo(V) catalyst system was very effective for St polymerization.

Facile synthesis of highly disperse Ni–Co nanoparticles over mesoporous silica for enhanced methane dry reforming

Nanoscale ◽  
2018 ◽  
Vol 10 (14) ◽  
pp. 6409-6425 ◽  
Author(s):  
Subhasis Das ◽  
Manideepa Sengupta ◽  
Arijit Bag ◽  
Mumtaj Shah ◽  
Ankur Bordoloi
Keyword(s):  
Mesoporous Silica ◽  
Catalyst System ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
Facile Synthesis ◽  
Methane Dry Reforming ◽  
Synergistic Approach ◽  
Co Nanoparticles ◽  
Cobalt And Nickel

A synergistic approach was made to develop a highly stable and carbon resistant catalyst system based on cobalt and nickel supported over modified mesoporous silica for the dry reforming of methane (DRM).

Bioinspired Complex-Nanoparticle Hybrid Catalyst System for Aqueous Perchlorate Reduction: Rhenium Speciation and Its Influence on Catalyst Activity

ACS Catalysis ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 511-522 ◽  
Author(s):  
Jinyong Liu ◽  
Jong Kwon Choe ◽  
Yin Wang ◽  
John R. Shapley ◽  
Charles J. Werth ◽  
...  
Keyword(s):  
Catalyst Activity ◽  
Catalyst System ◽  
Hybrid Catalyst ◽  
Perchlorate Reduction

scholarly journals Catalytic Hydrogen Evolution of NaBH4 Hydrolysis by Cobalt Nanoparticles Supported on Bagasse-Derived Porous Carbon

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3259
Author(s):  
Yiting Bu ◽  
Jiaxi Liu ◽  
Hailiang Chu ◽  
Sheng Wei ◽  
Qingqing Yin ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Porous Carbon ◽  
Density Functional ◽  
Hydrogen Generation ◽  
Degradation Mechanism ◽  
Catalyst Activity ◽  
Alkaline Solutions ◽  
High Dispersion ◽  
Co Nanoparticles ◽  
Catalytic Hydrogen Evolution

As a promising hydrogen storage material, sodium borohydride (NaBH4) exhibits superior stability in alkaline solutions and delivers 10.8 wt.% theoretical hydrogen storage capacity. Nevertheless, its hydrolysis reaction at room temperature must be activated and accelerated by adding an effective catalyst. In this study, we synthesize Co nanoparticles supported on bagasse-derived porous carbon (Co@xPC) for catalytic hydrolytic dehydrogenation of NaBH4. According to the experimental results, Co nanoparticles with uniform particle size and high dispersion are successfully supported on porous carbon to achieve a Co@150PC catalyst. It exhibits particularly high activity of hydrogen generation with the optimal hydrogen production rate of 11086.4 mLH2∙min−1∙gCo−1 and low activation energy (Ea) of 31.25 kJ mol−1. The calculation results based on density functional theory (DFT) indicate that the Co@xPC structure is conducive to the dissociation of [BH4]−, which effectively enhances the hydrolysis efficiency of NaBH4. Moreover, Co@150PC presents an excellent durability, retaining 72.0% of the initial catalyst activity after 15 cycling tests. Moreover, we also explored the degradation mechanism of catalyst performance.

Characterization of Ferromagnetic Nanoparticles Produced by A Carbon Arc

1994 ◽  
Vol 359 ◽  
Author(s):  
E. M. Brunsman ◽  
S. Anna ◽  
S. A. Majetich ◽  
M. E. Mchenry
Keyword(s):  
Fine Particles ◽  
Weight Percent ◽  
Buffer Gas ◽  
Switching Field ◽  
Interparticle Interactions ◽  
Carbon Coated ◽  
Carbon Arc ◽  
Co Nanoparticles ◽  
Percent Cobalt

ABSTRACTThe effect of increasing metal fraction on carbon arc nanoparticle production is examined for 10–50 weight percent cobalt starting materials. With 500 Torr of helium buffer gas, the carbon arc process yields carbon-coated FCC Co nanoparticles of similar sizes throughout this range. The saturation magnetization is believed to scale linearly with the relative abundance of Co. The variation in the coercivity with abundance is small compared to the dramatic changes which can arise from changes in the size of fine particles. The approach to magnetic saturation is more rapid in high abundance samples. This is attributed to interparticle interactions which align the easy axes when the nanoparticles crystallize within interconnected carbon shells. The switching field distribution as a function of Co abundance arises from both rotational barriers and from barriers due to the particle size distribution.

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