CuO Particle Size Research Articles

Feeding nanoparticles of copper oxide coated with lysine with or without added antagonists affects the copper status but not the performance of Holstein dairy cows

The apparent absorption of copper (Cu) in ruminants is low, with between 0.01 and 0.07 g/g absorbed from sources such as copper oxide (CuO) under typical feeding conditions, resulting in high levels of excretion. Improving the bioavailability of Cu could reduce the supplemental amount required to maintain Cu status and reduce excretion, particularly in the presence of dietary antagonists such as sulfur (S) and molybdenum (Mo). The objective of our study was to determine the Cu status of cows when fed nanoparticle CuO coated with Lys compared with conventional CuO when fed without or in combination with antagonists to Cu absorption (S and Mo) in the diet of dairy cows. Fifty-six multiparous Holstein-Friesian cows that were 48 d ± 17.2 (mean ± SD) postcalving and yielding 41 ± 6.4 kg of milk per day were used in a 2 × 2 factorial design. The 4 treatment groups were: CuO (O-), CuO with added antagonists (O+), nano CuO with a lysine coating (N-), and nano CuO with a Lys coating with added antagonists (N+), fed for 16 wk. We formulated the diets to contain ∼17 mg of Cu/kg DM, and diets with antagonists contained an additional 1 g of S/kg DM and 6 mg of Mo/kg DM, with Lys added to O- and O+ to provide the same daily supply as N- and N+. Blood samples were collected at wk 0, 2, 4, 6, 10, and 16, and liver biopsy samples at wk 0 and 16. We found no effect of dietary treatment on DMI, milk yield, live weight, or BCS, with mean values of 23.3 kg/d, 40.1 kg/d, 646 kg, and 2.68, but milk SCC was higher in cows fed conventional compared with nano CuO, or added compared with no added antagonists. We also found no effect of treatment on blood activity of gamma glutamyl transferase, superoxide dismutase, or ceruloplasmin, hematology profile, or plasma Cu and iron concentration. We found that plasma Mo concentration was increased from 0.36 µmol/L in cows fed O- or N- to 0.80 µmol/L in those receiving O+ or N+. Additional dietary antagonists also decreased the concentration of Cu in the liver of cows fed conventional CuO (C+) over the study period by 1.3 mg/kg DM per day, but in cows fed dietary antagonists and nano CuO coated with Lys (N+), liver Cu concentration was increased by 1.1 mg/kg DM per day. Our study is the first to demonstrate that reducing the particle size of CuO into the nano scale with a lysine coating improves the bioavailability of CuO in the presence of dietary antagonists in dairy cattle, and we did not observe any negative effects on performance or health.

Impact of Cu complex anions on CuZnAl intercalated hydrotalcite-like catalysts for low-carbon alcohols synthesis from syngas

Elucidating the structure-performance relationship of catalysts for low-carbon alcohols synthesis from syngas is crucial for designing efficient catalysts. In this study, CuO particle size, reducibility, and the number of oxygen vacancies could be adjusted by changing intercalated Cu complex anions, thereby affecting the catalyst's performance. The characterization results indicated that the insertion of [Cu(C2O4)2]2- between ZnAl layered double hydroxide resulted in the largest CuO particles (26.5 nm), leading to an increase in the metallic copper surface area. Consequently, the highest CO conversion (13.0 %) was achieved without altering alcohol distribution. On the other hand, when [Cu(EDTA)]2- was inserted, the catalyst possessed the smallest CuO particle size (8.9 nm), more abundant oxygen vacancies, and enhanced interaction between Cu species and ZnO, which promoted carbon chain growth and resulted in a high C2+OH proportion of 75.8 %. Our study thus provides a new perspective on catalyst structures for the syngas production of low-carbon alcohols.

Larvicidal activity of CuO and ZnO nanoparticles against Aedes aegypti and Anopheles stephensi mosquito vectors-a greener approach by Phaseolus vulgaris L. aqueous extract as bio-reductant

In order to eradicate mosquito-borne diseaseslikemalaria,chikungunya, dengue,and Zika virus which are mostly found in temperate zones, synthetic pesticides are widely used as a form of fumigation. This has resulted in a rise in mosquito-borne disease transmission dynamics and a substantial rise in atmospheric pollution. In light of this, the current work used an aqueous extract of Phaseolus vulgaris to formulate bioencapsulated CuO and ZnO NPs to combat mosquito vectors. The synthesized CuO and ZnO NPs were characterized using UV–visible, XRD, FT-IR, FE-SEM & EDX, AFM, and DLS techniques. According to analytical characterization, the CuO and ZnO NPs had monoclinic and hexagonal crystallites with average sizesof 13.7 nm and 185 nm, respectively. FE-SEM analysis confirms the spherical and flower-like morphology of CuO and ZnO NPs and their respective elemental composition was identified by EDX studies. The average particle size of CuO and ZnO NPs was determined to be 22.6 nm and 662 nm. CuO and ZnO NPs possessed zeta potential values of −23.2 mV and −29.7 mV respectively. The larvae of the malaria vector Anopheles stephensi and the dengue vector Aedes aegypti were subjected to compare the larvicidal bioassays in a range of concentrations of P. vulgaris aqueous extract with methanol extracts, and CuO NPs with ZnO NPs (6.25, 12.5, 25, 50, 100 µg/mL). The results showed the larvicidal activity of the aqueous extract is superior to the methanol extract and ZnO NPs are superior to the CuO NPs. This study further revealed that Aedes aegypti vulnerable than Anopheles stephensi to a given concentration of crude aqueous, methanol extracts of P. vulgaris and to CuO and ZnO NPs. The overall findings of this research demonstrated the feasibility of using these biosynthesized nanoparticles as highly effective, eco-friendly natural mosquito control pesticides.

Effect of CuO species and oxygen vacancies over CuO/CeO2 catalysts on low-temperature oxidation of ethyl acetate

The catalytic oxidation of ethyl acetate (EA) was studied over CuO/CeO2 catalysts which were prepared by ball milling with different precursors (copper oxide, cerium acetate, cerium dioxide, copper acetate and cerium hydroxide). The CuO/CeO2 catalyst (O-A) prepared with copper oxide and cerium acetate as precursors shows very high catalytic activity that 100% EA conversion is achieved at low temperature of 220 °C. It is found that specific surface area (112.8 m2/g), particle size of CuO (3.5 nm) and proportion of oxygen vacancies are prominent on the O-A catalyst. Oxygen vacancies in CeO2 support are beneficial to enhancing the adsorption and activation of the oxygen. More finely dispersed CuO particles and oxygen vacancies which are derived from the synergistic interaction of Cu–Ce species play an important role in the catalytic oxidation of EA.

The Effect of Cytotoxicity and Antimicrobial of Synthesized CuO NPs from Propolis on HEK-293 Cells and Lactobacillus acidophilus.

Drug resistance is currently possible anywhere in the world. Due to the discovery of antimicrobials, medicine, and health have made tremendous advances over the past several decades. This research evaluated the antimicrobial and cytotoxicity effects of green synthesis of copper oxide nanoparticles (CuO NPs) on Lactobacillus acidophilus and human embryonic kidney 293 cells (HEK). Method and Materials. Propolis was sampled and extracted. Green synthesis of CuO NPs was synthesized and characterized using SEM, TEM, DLS, BET, and zeta potential methods. L. acidophilus (ATCC 4356) was used, and the antimicrobial tests were carried out at different concentrations (10≥ mg/ml). Moreover, the cytotoxicity was evaluated using an MTT assay on human embryonic kidney 293 cells (HEK). Synthesized CuO NPs using propolis extracts from Khalkhal (sample 1) and Gillan (sample 2) showed -13.2 and -14.4 mV, respectively. The hydrodynamic sizes of well-dispersed samples 1 and 2 were 3124.9 nm and 1726.7 nm, respectively. According to BET analysis, samples 1 and 2 had 5.37 and 8.45 m2/g surface area, respectively. The surface area was decreased due to the addition of propolis extract, and the pore size was increased. CuO NPs of samples 1 and 2 were visible on SEM images with diameters ranging from 75 to 145 nm and 120 to 155 nm, respectively. Based on TEM analysis, the size of CuO particles was increased in samples 1 and 2. CuO NPs particles had narrow size distributions with evenly dispersed NPs on all sides. The cell viability of the CuO NPs of samples 1 and 2 after 24, 48, and 72 hours was greater than 50%. As a result of the MIC and MBC tests, it was determined that samples 1 and 2 had the same effect against L. acidophilus (0.0024 mg/ml). Biofilm formation and degradation of sample 1 were more efficient against L. acidophilus. There was no evidence of cytotoxicity in the samples. In addition, results showed that the green synthesized CuO NPs from Khalkhal propolis were effective against L. acidophilus. Thus, the green synthesized CuO NPs from Khalkhal propolis were the best candidates for clinical application.

Effect of Synthesis Conditions on the Catalytic Performances of CuO/Al2O3 in Microwave-enhanced Fenton-like System

Background: In previous work, we successfully prepared CuO/Al2O3 catalysts and evaluated their catalytic activity, kinetics and degradation mechanism for Fenton-like oxidation of p-nitrophenol (PNP) under microwave irradiation. However, we did not study the effect of important preparation parameters on the activities of catalysts. Objective: (1) The effect of preparation conditions: CuSO4 concentration of the impregnating solution, Al2O3 to CuSO4 solution ratio, type and concentration of precipitant and calcination temperature on the physico-chemical properties and catalytic activity were studied. (2) The catalytic performance of the Fenton-like oxidation reaction of PNP under microwave irradiation was evaluated and correlated with the characterization results. (3) The stability and catalytic mechanism of the catalysts were investigated. objective: (1) The effect of preparation conditions: CuSO4 concentration of impregnating solution, Al2O3 to CuSO4 solution ratio, type and concentration of precipitant and calcination temperature on the physico-chemical properties and catalytic activity were studied. (2) The catalytic performance of the Fenton-like oxidation reaction of PNP under microwave irradiation was evaluated and correlated with the characterization results.(3) The stability and catalytic mechanism of the catalysts were investigated. Methods: The CuO/Al2O3 catalyst was prepared by the impregnation deposition method. The 20 g pretreated Al2O3 particles were immersed in 0.6 mol/L Cu (NO3)2 solution and 0.4 mol/L NaOH solution for 24 h before and after. After cleaning and drying, the samples were calcined in an air muffle furnace for 4 h at a certain temperature to obtain CuO/Al2O3 catalyst. Then the catalyst was characterized and catalyzed. method: The CuO/Al2O3 catalyst was prepared by impregnation deposition method. The 20 g pretreated Al2O3 particles were immersed in 0.6 mol/L Cu (NO3)2 solution and 0.4 mol/L NaOH solution for 24 hours before and after. After cleaning and drying, the samples were calcined in an air muffle furnace for 4 hours at a certain temperature to obtain CuO/Al2O3 catalyst. Then the catalyst was characterized and catalyzed. Results: XRD, BET and FESEM results have demonstrated that the catalyst claimed at 300 and 350 ℃ showed a smaller size, a higher specific surface area and a better distribution of the CuO species than their counterparts prepared at higher calcination temperatures. The CuO/Al2O3 catalyst claimed at 300 and 350 ℃ also showed higher removal efficiencies for PNP than other catalysts prepared at higher calcination temperatures. result: XRD, BET and FESEM results have demonstrated that the catalyst claimed at 300 and 350 ℃ showed a smaller size, a higher specific surface area and a better distribution of the CuO species than their counterparts prepared at higher calcination temperatures. the CuO/Al2O3 catalyst claimed at 300 and 350 ℃ also showed higher removal efficiencies for PNP than other catalysts prepared at higher calcination temperatures. Conclusion: It was found that the catalysts prepared at 350 ℃ as calcination temperature showed higher surface area, smaller CuO particle size, and uniform CuO particle size distribution, and consequently showed better catalytic activities with better stability and reusability. Moreover, the XPS results of the catalysts showed a decrease in the Isat/Ip ratio after microwave enhanced Fenton-like reaction, confirming that CuO species has been reduced to Cu2O to some extent.

Modification of DSSC Based on Polymer Composite Gel Electrolyte with Copper Oxide Nanochain by Shape Effect.

Solvent evaporation and leakage of liquid electrolytes that restrict the practicality of dye-sensitized solar cells (DSSCs) motivate the quest for the development of stable and ionic conductive electrolyte. Gel polymer electrolyte (GPE) fits the criteria, but it still suffers from low efficiency due to insufficient segmental motion within the electrolytes. Therefore, incorporating metal oxide nanofiller is one of the approaches to enhance the performance of electrolytes due to the presence of cross-linking centers that can be coordinated with the polymer segments. In this research, polymer composite gel electrolytes (PCGEs) employing poly (vinyl butyral-co-vinyl alcohol-co-vinyl acetate) (P(VB-co-VA-co-VAc)) terpolymer as host polymer, tetrapropylammonium iodide (TPAI) as dopant salt, and copper oxide (CuO) nanoparticles as the nanofillers were produced. The CuO nanofillers were synthesized by sonochemical method and subsequently calcined at different temperatures (i.e., 200, 350, and 500 °C), denoted as CuO-200, CuO-350, and CuO-500, respectively. All CuO nanoparticles have different shapes and sizes that are connected in a chain which impact the amorphous phase and the roughness of the surface, proven by the structural and the morphological analyses. It was found that the PCGE consisting of CuO-350 exhibited the highest ionic conductivity of 2.54 mS cm−1 and apparent diffusion coefficient of triiodide of 1.537 10−4 cm2 s−1. The enhancement in the electrochemical performance of the PCGEs is correlated with the change in shape (rod to sphere) and size of CuO particles which disrupted the structural order of the polymer chain, facilitating the redox couple transportation. Additionally, a DSSC was fabricated and achieved the highest power conversion efficiency of 7.05% with JSC of 22.1 mA cm−2, VOC of 0.61 V, and FF of 52.4%.

The Effect of Copper and Copper Oxide Nanoparticles on Rainbow Trout (Oncorhynchus mykiss W.) Spermatozoa Motility after Incubation with Contaminants.

The study aimed to analyse the effect of copper nanoparticles of similar particle size of Cu and CuO and copper ions (CuSO4) on the motility parameters of rainbow trout spermatozoa after long-term exposure and compare its harmful effect. Nanoproducts of Cu and CuO (Cu NPs, CuO NPs) of primary particle size around 50 nm and ionic solution of CuSO4 were used for the study. Suspension of concentrations 0, 1, 5, 10, 25, and 50 mg Cu·L−1 of Cu NPs, CuO NPs, and CuSO4 was dissolved in an artificial seminal plasma. Milt was mixed with the prepared solution and stored in a fridge, at 6 °C, for 96 h. At the defined incubation time, spermatozoa were activated for movement, and six motility parameters were evaluated using an automated system (CASA). Increasing concentrations of Cu NPs, CuO NPs, and CuSO4 in an incubation medium in parallel decreased the percentage of motile sperm (MOT). The effect of Cu NPs and ionic copper on MOT was more deleterious than that of CuO NPs. Copper products slightly increased the velocity (VCL) compared to the control, particularly up to 24 h of storage. Linearity (LIN) was improved by three tested products, particularly CuO NPs. Generally, the motility duration was prolonged when the sperm was incubated with copper products compared to the control. Nanoproducts made from different compounds of the same elements of similar particle size have a different effect on cells. Cu NPs were more harmful than CuO NPs. The effect of Cu NPs was similar to an ionic form of CuSO4. When incubated, the copper nanoproducts and ionic form exert a slightly positive effect on spermatozoa velocity, linearity, and motility duration, particularly up to 24 h of storage.

Synthesis of ZnO and CuO nanoparticles via Sol gel method and its characterization by using various technique

Nanotechnology is a completely unique branch of technology that offers with substances in a very small size between (1–100 nm) with various crystal shapes. Metals have ability to produce large number of oxides. These metal oxides play a major role in many areas of chemistry, physics, material science and food science. In this research, Zinc Oxide (ZnO) and Copper (II) oxide nanoparticles were synthesized via sol–gel process using zinc nitrate and copper (II) nitrate as precursor respectively. The characterization of CuO and ZnO nanoparticles was done by using various techniques. X-ray Diffraction (XRD) indicates the crystallinity and crystal size of CuO and ZnO nanoparticle. Fourier transform infrared spectroscopy (FT-IR) was used to get the infrared spectrum of the sample indicating composition of the sample which contains various functional groups. XRD result shows the particle size of CuO at highest peak 29.40140 was 61.25 nm and the particle size of ZnO at highest peak 36.2476° was 21.82 nm. FT-IR spectra peak at 594.56 cm-1 indicated characteristic absorption bands of ZnO nanoparticles and the broad band peak at 3506.9 cm−1 can be attributed to the characteristic absorption of O–H group. The analysis of FT-IR spectrum of CuO shows peaks at 602.09, 678.39, and 730.19 cm−1 which refer to the formation of CuO. SEMimages indicate the morphology of CuO and ZnO nanoparticles. Result of EDX characterization indicates that the both synthesized nanoparticles have good purity with very less amount of impurities. EDX data indicates that Cu content was 54.56%, oxygen content was 33.75% in CuO nanoparticles and Zn determined by EDX was 40.77 and O was 45.82 in ZnO.Graphical

Effect of Cu-ZSM-5 catalysts with different CuO particle size on selective catalytic oxidation of N,N-Dimethylformamide

Effect of Cu-ZSM-5 catalysts with different CuO particle size on selective catalytic oxidation of N,N-Dimethylformamide

Rapid electron transfer boosts CuO-Mediated nonradical oxidation pathways for efficient removal of Bisphenol A

CO2 emission reduction and CO2 capture during wastewater treatment are the main objectives of carbon neutral wastewater treatment. Here, we show that CuO is expected to promote non-radical oxidation pathways through enhanced electron transfer. Calcination temperature may affect crystal growth and microscopic strain, and the smaller particle size of CuO provides shorter distance nanochannels for core-shell diffusion of electrons/defects. This facilitates fast electron transfer and easy in/out diffusion of electrons/defects, thus promotes 1O2-mediated nonradical oxidation (13.6-fold increase in kinetic reaction rate). A kinetic model was developed to predict the kinetic reaction rate constants of CuO/peroxymonosulfate (PMS) under different parameter conditions. The degradation pathways and product toxicity of pollutants are explored through Frontier Molecular Orbital Theory (FMO) and the Toxicity Estimation Software Tool (TEST). Due to the alkaline environment and the mild oxidation capacity of 1O2-mediated nonradical oxidation pathway, CuO/PMS system can not only effectively detoxify toxic organic pollutants without complete mineralization (emitting large amounts of CO2), but also capture CO2 and convert it into stable carbonates for environmental use. This study demonstrates the ability of CuO/PMS to effectively treat toxic organic pollutants in a practical microreactor, and provides a viable pathway for carbon neutral wastewater treatment.

ZnAl layered double hydroxide based catalysts (with Cu, Mn, Ti) used as noble metal-free three-way catalysts

This research presents a novel approach for developing noble metal-free three-way catalysts by using ZnAl layered double hydroxide (LDH) co-precipitated with Mn and Ti. Cu was added as the catalytically active metal. Two methods were explored, namely the addition of Cu during the co-precipitation step and a post-synthesis method using the LDH memory effect. In case the starting material had LDH characteristics high amounts of CuO were adsorbed on the support and high dispersion degrees of CuO were obtained. A four-cycle three-way catalysis test was used for evaluation. The smaller CuO particle size resulted in better performance for oxidation reactions. The addition of Mn had a positive effect on the general performance of the catalysts, while the presence of Ti mainly improved the NO conversion. The developed materials showed good stability in consecutive catalytic testing cycles and even show some NO conversion under stoichiometric conditions. The developed CuO-based ZnAl layered double hydroxide-based materials are very promising catalysts for Three-way catalysis, allowing to reduce the precious metal content compared to the classical catalysts composition.

Evaluation of pharmacological and catalytic activity of CuO and Zn doped CuO nanoparticles

CuO and Zn doped CuO nanoparticles (Zn-CuO NPs) with varying concentration i.e., ZnxCu1−xO (where x = 0, 0.5, 1, and 1.5%) have been prepared via microwave assisted method. The spheroid structure of CuO NPs and the nanorod structure of ZnCuO NPs have been determined using High Resolution Scanning Electron Microscopy (HR-SEM) analysis. Elemental analysis has been carried out using Energy Dispersive X-ray Analysis (EDAX). The particle size and surface area of CuO and Zn-CuO NPs have been confirmed by Brunauer–Emmett–Teller (BET) method. The antibacterial studies have been revealed that Zn(1.5%)-CuO NPs exhibited maximum zone of inhibition (19-29 mm) against the tested four bacterial strains. Zn-CuO NPs have been displayed robust action of antibacterial activity with minimum inhibitory concentration (MIC) of 0.09 µM against Campylobacter coli (C. Coli). DPPH and H2O2 radical scavenging assay investigation have been revealed that the significant scavenging activity has showed by Zn(1.5%)-CuO. The in vitro cytotoxicity evaluation of synthesized material against human breast (MCF7) and human lung (A549) cancer cell lines have been demonstrated that Zn(1.5%)-CuO NPs exhibited better cytotoxic activity against MCF7 cell lines (97.5% cell death) than A549 cell lines (90% cell death).

The Effect of Particle Size of Copper Oxide (CuO) on the Heat‐Induced Catalysis Decomposition of Molecular Perovskite‐Based Energetic Material DAP‐4

In this study, the effect of copper oxide (CuO) with different sizes on the heat‐induced catalysis decomposition of typical molecular perovskite‐based energetic material DAP‐4 was studied. Pure CuO with different sizes and DAP‐4 are characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Heat‐induced catalysis decomposition performances of DAP‐4 with adding CuO were investigated by differential scanning calorimeter (DSC). Results demonstrated that with a lower‐addition CuO at the nanoscale added (1 wt%), DAP‐4 had decreased at least by 36°C with the heating rate of 10°C/min, compared with pure DAP‐4. With the CuO particle size of 50 nm, the Ea of DAP‐4 heat‐induced decomposition in DAP‐4/CuO‐50 had reduced from 159.8 kJ/mol to 120.2 kJ/mol, which is lower than DAP‐4/CuO‐150. The heat‐induced catalysis decomposition mechanism of DAP‐4 by using CuO as a nanoadditive was proposed.

Simple preparation of Ni/CuO nanocomposites with superior sensing activity toward the detection of methane gas

Composite nanostructures composed of transition metal oxides are promising materials in catalyst, supercapacitor, and gas sensors. Here we have used Ni for the enhancement of the CuO gas sensor toward methane gas. High-quality Nix/CuO nanocomposites (where x = 0.0 to 10%) have been synthesized by the simple method of solid–solid reaction. A nanoparticle structure was obtained. The size of the nanoparticle can be controlled easily by adjusting the relative Ni concentration in Ni/CuO nanoparticles. The relative diffusion amount of Ni to CuO was proved to be the key factor to influence the sensing sample properties. XRD patterns and HRTEM image confirmed the preparation of Nix/CuO phase, which showed a decline in crystallite size from ~ 17.8 to 14.6 nm (XRD). FESEM and TEM images also exhibited the effect of Ni content on the particle size of CuO. EDX mapping confirmed that the NiO fine particles were distributed semi-uniform at low Ni concentration; however, they aggregated at high Ni concentration. The sensing properties were done at different temperatures and various concentrations of methane gas. It was illustrated that the increase of Ni up to 5% showed an improvement in the sensor response of CuO toward methane compared to the pure phase of CuO and NiO, as well. The maximum-response temperature was 250 °C at which the sensor response is ~ 4.9 (390%), which is four times higher than the CuO and NiO pure phases. The present nanocomposites could detect CH4 at lower levels of explosive level (5%). The mechanism of gas sensing is explained depending on the electronic structure changes.

Fabrication of CuO/TiO2/Ti Monolithic Catalyst for Efficient and Stable CO Oxidation

AbstractThis work reports a novel strategy to in situ grow TiO2 nanosheets on flexible Ti mesh as ideal support, and to modify CuO active components through multi‐step methods. The CuO/TiO2/Ti monolithic catalyst can realize the complete CO oxidation at 110 °C without the assistance of any noble metal and the outstanding long‐term stability can be also achieved. When using urea as deposition precipitant, CuO particle size will increase obviously with the reaction time longer than 6 h, which is adverse to the catalytic performance, showing the significant impact of CuO particle size on the CO oxidation capability. The deposition reaction carried out in different solutions is also investigated and the results show that CuO/TiO2/Ti catalysts synthesized in acid and alkaline condition exhibit superior catalytic performance owing to the high content of Cu1+/0 and adsorbed oxygen species (Oα) on surface, large surface area, and excellent redox capacity compared with that in reductive solution. More importantly, the as‐synthesized CuO/TiO2/Ti monolithic catalysts show outstanding low‐temperature performance and excellent long‐term stability, indicating the overwhelming advantage of in situ grown catalysts. It is expected that the peculiar in situ growth technology is capable of extending to monolithic catalysts for multiple applications in the future.

Effect of CuO and SnO2 particle size on hot extrusion deformation of AgCuOSnO2: Finite element simulation and experimental study

Effect of CuO and SnO2 particle size on hot extrusion deformation of AgCuOSnO2: Finite element simulation and experimental study

Influence of aloe-vera gel mediated CuO coated LiNiPO4 cathode material in rechargeable battery applications

In this work, we report the synthesis and electrochemical performance of CuO synthesized in aloe-vera gel medium coated LiNiPO4 in first time also, we compared the performance of CuO prepared in water medium coated LiNiPO4. The particle size of pure LiNiPO4 is 5.2 μm and the particle size of CuO prepared in water medium coated LiNiPO4 is 2.1 μm. Also, the particle size of CuO prepared in aloe-vera gel medium coated LiNiPO4 is 1.7 μm, which is analysed by using particle size analysis. As we expected, aloe-vera gel mediated CuO effectively reduces the particle size of LiNiPO4 also it exhibits the good electrochemical performance which is examined with the help of charge/discharge analysis. Green synthesis is an operative method to prepare surface coating materials for cathode materials of lithium ion batteries.

Hydroprocessing of oleic acid for the production of aviation turbine fuel range hydrocarbons over bimetallic Fe-Cu/SiO2-Al2O3 catalysts promoted by Sn, Ti and Zr

In this work, the synergistic effects of 1 wt.% Ti, 1 wt.% Zr, and Sn in the range of 0.5−2 wt.% on Fe(3)-Cu(13)/SiO2-Al2O3 catalyst were ascertained through extensive characterization and their subsequent evaluation for the production of aviation turbine fuel range hydrocarbons (C8-C16) via hydroprocessing of oleic acid. The largest surface area (571 m2/g) and pore volume (0.65 cm3/g) were obtained from the N2 physisorption analysis of 1 wt.% Sn-promoted catalyst (E). Cu2O and CuO were identified in the X-ray diffractograms (XRD) of all the catalysts except for catalyst E, which revealed only the peaks of Cu2O owing to the small particle size of CuO below the threshold of detection of XRD. X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of both oxidized and reduced phases of Cu, Fe, Ti, Zr and Sn in their respective catalysts, with the highest and lowest atomic compositions of reduced Fe and CuO, respectively, detected in catalyst E; corroborating findings from XRD analyses. The relatively homogeneous dispersion of phases present in catalyst E (revealed by its smallest crystallite size of 5.1 nm) was also evidenced by the weakest metal-support interaction from the H2-TPR analysis of the same catalyst. Hydroprocessing of oleic acid using catalyst E at 320 °C under H2 pressure of 2.1 MPa and reaction time of 8 h resulted in the highest aviation turbine fuel range hydrocarbons selectivity of 76.8 % and yield of 71.7 %. This was due to its high metal dispersion, desirable textural properties and high oxophilic reduced iron content.

Comparison of hydrogen consumption behavior of chromium and manganese promoted copper-based catalysts

CuO/ZnO/Al2O3/MgO–Cr and -Mn catalysts are synthesized using nitrate route via co-precipitation method. The precursors are characterized by XRD. The decomposition behavior of the precursors is analyzed by Air-TGA. The catalysts calcined at 250, 300, 350 and 450 °C are characterized by XRD and BET. CuO particle size reduction and surface area of the catalysts are investigated. Increasing the calcination temperature from 350 °C to 450 °C crystallite size increases about 3 nm, and BET surface area decreases about 30 m2/g. The reduction characteristics of the catalysts are analyzed via TPR and H2-TGA, and H2 consumption values of Cr and Mn containing catalysts is found as 40% and 60%, respectively. Peak temperatures of Mn containing catalysts (290–325 °C) are lower than peak temperatures of Cr containing catalysts (300–360 °C) as confirmed by H2-TGA and H2-DTG. The optimum H2 consumption value of 52% is obtained with CuO/ZnO/Al2O3/MgO–Mn catalyst calcined at 350 °C.