The Catalytic Activity Of Copper Oxide Nanoparticles Towards Carbon Monoxide Oxidation Catalysis: Microwave – Assisted Synthesis Approach

In this research, we report a simple, versatile, and reproducible method for the synthesis of copper oxide nanoparticles via microwave assisted synthesis approach. The important advantage of this catalyst is due to its important role not only in the low temperature oxidation of CO but also in potential applications in pharmaceutical and fine chemical synthesis. The results reveal that the copper oxide catalyst has particularly a remarkable high activity for CO oxidation catalysis as it was found that copper oxide (CuO) catalyst has 100% conversion of carbon monoxide into carbon dioxide at 175 oC. This also could be attributed to the high degree of dispersion of the copper oxide nanoparticles with a particle size of 25-35 nm. Those nanoparticles were characterized by various spectroscopic techniques including; X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM)

Laser Vaporization And Controlled Condensation (LVCC) Of Graphene Supported Pd/Fe3O4 Nanoparticles As An Efficient Magnetic Catalysts For Suzuki Cross – Coupling

Herein, a reproducible, reliable, and efficient method was reported for the synthesis of palladium nanoparticles dispersed on a composite of Fe3O4 and graphene (Pd-Fe3O4/G) as a highly efficient active catalyst for being used in Suzuki cross–coupling reactions. Graphene supported Pd/Fe3O4 nanoparticles (Pd-Fe3O4/G) exhibit a remarkable catalytic performance towards Suzuki coupling reactions. Moreover, the prepared catalyst could be recycled for up to three times with high catalytic activity. The catalyst was prepared using LVCC synthesis; the prepared catalyst is highly magnetic which provides a platform to facilitate the separation process of the catalyst through applying an external magnetic field using a magnet. This adopted approach has several advantages including recyclability, mild reaction conditions, and reproducibility. The high catalytic activity is due to the catalyst-support strong interaction. Moreover, the defect sites found on reduced GO nanosheets act as nucleation centers providing a platform to anchor Pd and Fe3O4 nanoparticles and hence avoid the potential agglomeration and subsequently the anticipated decrease in the catalyst catalytic activity as a direct impact for this unfavorable agglomeration

Polyvinylpyrrolidone - Reduced Graphene Oxide - Pd Nanoparticles as an Efficient Nanocomposite for Catalysis Applications in Cross-Coupling Reactions

This paper reported a scientific approach adopting microwave-assisted synthesis as a synthetic route for preparing highly active palladium nanoparticles stabilized by polyvinylpyrrolidone (Pd/PVP) and supported on reduced Graphene oxide (rGO) as a highly active catalyst used for Suzuki, Heck, and Sonogashira cross coupling reactions with remarkable turnover number (6500) and turnover frequency of 78000 h-1. Pd/PVP nanoparticles supported on reduced Graphene oxide nanosheets (Pd-PVP/rGO) showed an outstanding performance through high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method was used to prepare this efficient catalyst using microwave irradiation synthetic conditions. The synthesis approach requires simultaneous reduction of palladium and in the presence of Gaphene oxide (GO) nanosheets using ethylene glycol as a solvent and also as a strong reducing agent. The highly active and recyclable catalyst has so many advantages including the use of mild reaction conditions, short reaction times in an environmentally benign solvent system. Moreover, the prepared catalyst could be recycled for up to five times with nearly the same high catalytic activity. Furthermore, the high catalytic activity and recyclability of the prepared catalyst are due to the strong catalyst-support interaction. The defect sites in the reduced Graphene oxide (rGO) act as nucleation centers that enable anchoring of both Pd/PVP nanoparticles and hence, minimize the possibility of agglomeration which leads to a severe decrease in the catalytic activity.

Optimization Of The Catalytic Performance Of Pd/Fe 3 O 4 Nanoparticles Prepared Via Microwave-assisted Synthesis For Pharmaceutical And Catalysis Applications

Microwave assisted synthesis technique was used to prepare palladium supported on iron oxide nanoparticles. The advantage of using microwave irradiation as a synthetic tool is due to its unique features as a one step, simple, versatile, and rapid process. The reactants are added simply at room temperature without using high-temperature injection. Hydrazine hydrate was added by the following ratios (0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1, 1.6, and 3) ml to the different prepared samples at room temperature in order to investigate its effect on the catalytic performance of the prepared catalysts. The prepared catalyst could be used as an ideal candidate not only for pharmaceutical industry through cross-coupling reactions but also for low temperature oxidation catalysis of carbon monoxide and pharmaceutical applications as well. The experimental results showed that Pd/Fe3O4 catalyst has a remarkable catalytic activity for carbon monoxide oxidation catalysis due to the strong interaction between palladium and iron oxide nanoparticles. This may be due to the small particle size (7-14 nm) and concentration ratio of the Pd nanoparticles dispersed on the surface of magnetite (Fe3O4). Those nanoparticles were characterized by various spectroscopic techniques including; X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Vibrating Sample Magnetometer (VSM) and transmission electron microscopy (TEM)

Green Synthesis Of Copper Oxide Nanoparticles In Aqueous Medium As A Potential Efficient Catalyst For Catalysis Applications

In this research, we have developed a reliable green method for the synthesis of copper oxide nanoparticles as a potential efficient catalyst for several catalysis applications. In our experimental approach, microwave-assisted synthesis technique was used in order to perform chemical reduction of copper salt using hydrazine hydrate as a strong reducing agent. The prepared catalyst was characterized using various techniques showing the formation of well dispersed copper oxide nanoparticles. The synthesized Copper oxide catalyst shows many advantages including the use of environmentally benign solvent systems, green synthetic approach, and mild reaction conditions

Microwave-assisted Synthesis Of Palladium Nanoparticles Supported On Copper Oxide In Aqueous Medium As An Efficient Catalyst For Suzuki Cross-coupling Reaction

We report here a reliable green method for the synthesis of palladium nanoparticles supported on copper oxide as a highly active and efficient catalyst for Suzuki cross-coupling reaction. The experimental synthetic approach is based on microwave-assisted chemical reduction of an aqueous mixture of palladium and copper salt simultaneously using hydrazine hydrate as reducing agent. The catalyst was fully characterized using various techniques showing well-dispersed palladium nanoparticles. The catalytic activity and recyclability of the prepared catalyst were experimentally explored in the ligand-free Suzuki cross-coupling reaction with a diverse series of functionalized substrates. The synthesized Pd/CuO catalyst shows many advantages beside its high catalytic efficiency such as the recyclability of up to five times with negligible loss of catalytic activity, short reaction times, use of environmentally benign solvent systems, and mild reaction conditions

Bulletproof Vests/shields Prepared From Composite Material Based On Strong Polyamide Fibers And Epoxy Resin

Fiber Reinforced Plastics (FRP) have arisen as a main class of tactual materials having high strength and light weight implemented in a large scale of different applications. This study performs a comparison between the enhanced propidines of Kevlar 49 fiber and Twaron CT 704 reinforced with epoxy resin to obtain an efficient, light weight and slim body m o r capable of resisting high speed projectiles (9 mm bullets). Reinforcing the fabrics adds extra strength to the fabrics instead of using several unreinforced fabrics which increases the weight thickness and the cost of the final product. The response of the prepared composite material based on the two different fibers was studied by using a test barrel for the penetration test. In addition. indentation test is also au lied to compare between the mechanical properties of both laminates and determine which fabric is better for life protection application. The final results showed that using the technique of reinforcing the fabrics specially Twaron is much better where the final bulletproof shield has a smaller number of layers and was found lighter by 40% than those made by Kevlar

Synthesis, Characterization And Selected Application Of Chitosan-coated Magnetic Iron Oxide Nanoparticles

In this research, we report an efficient method to prepare highly active chitosan-coated magnetic iron oxide nanoparticles by implementing co-precipitation technique which is used for wastewater treatment applications. Chitosan-coated magnetic iron oxide nanoparticles were synthesized and characterized using TEM, XRD, and XPS. A comparative study has been made between chitosan powder and chitosan coated with magnetic nanoparticles with respect to the rate of adsorption of copper from aqueous solution. It was also experimentally verified that chitosan coated magnetic iron oxide nanoparticles are much more effective in adsorption of heavy metals than chitosan powder and it takes just few minutes instead of hours. Moreover, the super paramagnetic behavior of the chitosan coated with iron oxide nanoparticles enabled the easy removal through applying an external magnetic field and hence leaving the solution free from copper

Mechanical characteristics for different composite materials based on commercial epoxy resins and different fillers

In this research, different compositions of composite materials based on epoxy resin and four different fillers were prepared and all mechanical characteristics were investigated to reach a composite material having high resistance to impact by high kinetics energy projectiles which is required in the production of bulletproof jackets and also in cassette shields of explosive reactive armors to protect tanks. This composite material is usually applied as layers with other polymeric fibers such as carbon fibers and Kevlar (polyamide) sheets. The used epoxy consists of Epon as linear epoxy and tertiary amine as hardener. The used fillers are carbon black, magnesium carbonate, wood flour and sand. The pure thermoset epoxy (without filler) which gives the highest different mechanical properties is based on 10:5 by weight (linear Epon/Hardener). The composition which gave the highest resistance to impact by high kinetics energy projectiles was epoxy resin containing 15% by weight wood floor where the resistance to impact was increased by 32% when compared with the pure epoxy