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An efficient and sulfur resistant K-modified activated carbon for SCR denitrification compared with acid- and Cu-modified activated carbon

In this work and for the first time, an alkali metal potassium (K) as a promoter was loaded on an activated carbon (AC) to be used for selective catalytic reduction of NO from industrial flue gas. The denitrification activity of K-modified AC samples was investigated and compared with those of acid- and Cu-modified AC samples. The three modifications can enhance the denitrification activity of AC samples. To investigate the enhanced mechanisms of denitrification and SO2 resistance, various AC samples were characterized by SEM, EDX, XRF, ICP, XRD, N2 physisorption, H2-TPR, XPS, in situ DRIFTS and TPD. For the acid modification, the content of phenolic hydroxyl increases and then promotes the adsorption of NH3. For the loading of Cu, the appearance of Cu2+/Cu+ sites with high catalytic activity promotes NH3 and NO adsorption and changes the reaction pathway. For the loading of K, the adsorption capacity for NO increases nearly 12 times higher than that on Raw-AC, of which 85.0% is chemical adsorption. Moreover, three kinds of active nitrate species additionally forms, including nitro compounds, monodentate nitrate and nitrous oxide, which promote the denitrification reaction path. AC-Cu has poor sulfur resistance due to the sulfation of Cu, while AC-K show good sulfur resistance due to the enhanced adsorption of NO. The catalytic dissociation activity of N2O on AC-K makes the formation and decomposition of N2O into a dynamic equilibrium. As a result, AC-K has a high N2 selectivity, while AC-Cu has poor N2 selectivity.

Hydrogen generation from catalytic hydrolysis of sodium borohydride by a Cu and Mo promoted Co catalyst

Catalytic hydrolysis of chemical hydrides with the use of NaBH4 is a safe and effective way to provide hydrogen fuel for new energy vehicles and portable electronic devices. Herein we developed a Cu and Mo promoted Co hierarchical composites (Co1−xCuxMoO4) for hydrolysis of NaBH4 via an easy synthesis route. FESEM analysis depicts that the morphology of Co1−xCuxMoO4 hierarchical composites varied significantly from irregular microsphere to marigold microsphere to rose like morphology with the increase in Cu (x) ratio with respect to Co (1 − x). Flower-like morphological architecture and crystal configuration empower the supported catalyst to exhibit a remarkable catalytic activity and outstanding catalytic activity was obtained for marigold-like Co0.9Cu0.1MoO4 catalyst with an H2 generation rate of 1005.7 mL min−1 g−1, which confirms existence of synergistic effect between Co, Cu and Mo. Lower loading of Cu in Co1−xCuxMoO4 supported the active sites of Co to increase its catalytic activity. Additionally, the catalyst exhibits good recyclability after five successive runs of hydrolytic reaction, making it a robust catalyst for hydrolysis of NaBH4 and could be considered as a potential catalyst for portable hydrogen fuel systems.

Characterization, conductivity studies, dielectric properties, and gas sensing performance of in situ polymerized polyindole/copper alumina nanocomposites

AbstractConducting polymer composites of polyindole (PIN) and copper–alumina (Cu–Al2O3) nanocomposites were synthesized by in situ polymerization of indole with different contents of Cu–Al2O3 nanoparticles. The polymer nanocomposites were characterized by Fourier transform infrared (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray (EDX), transmission electron microscope (TEM), differential scanning calorimetry, thermogravimetric analysis, and ammonia gas sensing performance was also analyzed. FTIR and XRD studies revealed the attachment of Cu–Al2O3 in the molecular chain of PIN. The presence of bright trapezoid channels and variation in morphology for different loading of nanoparticles were confirmed by SEM and TEM. The attachment of Cu–Al2O3 nanoparticles in the PIN matrix was confirmed through EDX spectroscopy. The glass transition temperature and thermal stability of the composites were greatly enhanced with the loading of Cu–Al2O3. Enhancement in alternating current conductivity, dielectric constant and the current–voltage characteristics of the prepared composite revealed the semiconducting nature of the system with an increase in the loading of nanoparticles. Also, nanocomposite exhibited an excellent sensitivity and fast response to ammonia gas. The evaluated result of the present study suggested that Cu–Al2O3 reinforced PIN hybrid is a good candidate for the fabrication of electrochemical devices.

Ligand-free copper-catalyzed denitrogenative arylation of phosphorylamides with arylhydrazines

A straightforward arylation of phosphorylamides with arylhydrazines hydrochloride was herein demonstrated. The protocol proceeded in the presence of a catalytic loading of Cu(OAc)2 as the catalyst, DTBP as the external oxidant and Cs2CO3 as the base, but without any ligands. And a series of N-aryl phosphorylamides were successfully obtained in high efficiency (up to 93% yields) with good substituents compatibility (up to 30 examples). Free radical mechanism was proposed for the facile methodology based on the results of control reactions and literature explorations.

Influence of a bifunctional linker on the loading of Cu2AgInS4 QDs onto porous TiO2 NFs to use as an efficient photoanode to boost the photoconversion efficiency of QDSCs

Quaternary Cu2AgInS4 quantum dots anchored more onto porous TiO2 NFs through a linker, 3-mercaptopropionic acid exhibits higher photoconversion efficiency of QDSC than that of the same anchored without a linker.

Sonoprecipitation fabrication of enhanced electron transfer Cu(OH)2/g-C3N4 nanophotocatalyst with promoted H2-Production activity under visible light irradiation

A series of Cu(OH)2/g-C3N4 photocatalysts were fabricated via precipitation and sonoprecipitation. Various physicochemical and electrochemical techniques were employed to investigate the physical and optical properties of the samples, while their photocatalytic performance was studied based on the water splitting. Based on the observations, Cu(OH)2 was nominated as an stable and highly efficient non-precious cocatalyst for photocatalytic H2 generation. 4Cu(OH)2/C3N4(U) sample demonstrated the highest performance (187 μmol/h/g) among the other samples with various loading of Cu(OH)2 which is 31 times higher than pure C3N4. This enhancement was because of the important role of Cu(OH)2 as electron traps and active sites. Additionally, the photoactivity of the sono-synthesized photocatalyst was significantly higher than the one synthesized by precipitation method by 67%. The findings confirmed the promoting influence of ultrasound irradiation on providing well intimate cocatalyst-semiconductor interfacial contact, higher surface area and better dispersion of cocatalysts. This could facilitate the efficient transfer of electrons to cocatalyst and decrease charge carriers recombination where supported by PL, EIS and transient photocurrent results. This study addresses the sonochemical method as a promised rout for fabrication of a closely contact interface which is a key parameter to achieve more efficient noble metal free cocatalysts.

Effect of Broiler Litter Application Method on Metal Runoff from Pastures

Loss of metals from agricultural fields to surface water bodies causes deterioration of surface water quality. Method of application of broiler litter can affect loss of metals in surface runoff. Subsurface banding of broiler litter can decrease loss of P and N in surface runoff relative to surface application of broiler litter. However, limited research has been done to evaluate the impact of litter application method on loss of metals in surface runoff. Therefore, the objective of this research was to quantify differences in loss of metals in surface runoff from a tall fescue pasture as a function of method of application of broiler litter (i.e., surface vs. subsurface application). A rainfall simulation study was conducted in the Sand Mountain region of north Alabama. Results indicate that concentration and loadings of Cu, K, Mg, and Zn decreased in surface runoff as a result of application of broiler litter in subsurface bands and were similar between the subsurface‐banded broiler litter and control (no litter applied) treatments. Greater than 90% of the applied rainfall infiltrated, indicating that losses of metals via lateral and subsurface flows can be substantial. Overall, results of this study show that application of broiler litter in subsurface bands can reduce loss of metals in surface runoff. Future research studies should investigate the impact of method of application of broiler litter on the metal losses in leachate and subsurface flows.Core Ideas Broiler litter application method affects loss of metals in runoff. Subsurface banding of broiler litter reduced concentrations of metals in runoff. Loss of metals via lateral flow pathways could be significant in this region.

Effect of La-doped scheelite-type SrWO4 for photocatalytic H2 production

In this paper, we present a systematic investigation of the photocatalytic H2 production over the Sr1−1.5xLaxWO4 (0 ≤ x ≤ 0.2) solid solutions. The doped La3+ ion in the crystal structure was identified by the Le Bail fit on the X-ray diffraction pattern of the as-prepared sample. The cell volume of the doped sample was linearly decreased by the augmentation of the La3+ ion. The morphology and composition of Sr0.82La0.12WO4 were observed by the transmission electron microscope, scanning electron microscope, and X-ray photoelectron spectroscopy. And then the loading of Cu, Ag, Au, Pt, Ni, and Ru as cocatalysts on sub-crystallite Sr0.82La0.12WO4 sample for H2 production was studied. The optimum H2 production rate is 309.7 μmol/h/g for 1.5 wt% Ru/Sr0.82La0.12WO4, which is 3.1 times than the undoped sample. And its apparent quantum yield is 0.44% at 365 (± 15) nm. All the photocatalysts recycled after the photocatalytic reactions show no degradation.

Copper relay path through the N-terminus of Wilson disease protein, ATP7B

In human cells, copper (Cu) ions are transported by the cytoplasmic Cu chaperone Atox1 to the Wilson disease protein (ATP7B) in the Golgi for loading of Cu-dependent enzymes. ATP7B is a membrane-spanning protein which, in contrast to non-mammalian homologs, has six cytoplasmic metal-binding domains (MBDs). To address the reason for multiple MBDs, we introduced strategic mutations in which one, two or three MBDs had been blocked for Cu binding via cysteine-to-serine mutations (but all six MBDs are present in all) in a yeast system that probes Cu flow through Atox1 and ATP7B. The results, combined with earlier work, support a mechanistic model in which MBD1-3 forms a regulatory unit of ATP7B Cu transport. Cu delivery via Atox1 to this unit, followed by loading of Cu in MBD3, promotes release of inhibitory interactions. Whereas the Cu site in MBD4 can be mutated without a large effect, an intact Cu site in either MBD5 or MBD6 is required for Cu transport. All MBDs, expressed as single-domain proteins, can replace Atox1 and deliver Cu to full-length ATP7B. However, only MBD6 can deliver Cu to truncated ATP7B where all six MBDs are removed, suggesting a docking role for this structural unit.

Aqueous copper bioavailability linked to shipwreck-contaminated reef sediments

Pollution from the grounding or sinking of ships can have long lasting effects on the recovery and dynamics of coastal ecosystems. Research on the impact of copper (Cu) pollution from the 2011 MV Rena shipwreck at the Astrolabe Reef (Otaiti), New Zealand, 5 years after the grounding, followed a multi-method and multi-disciplinary approach. Three independent measures of aqueous Cu using trace-element-clean-techniques substantiate the presence of high total, total dissolved (<2 µm) and elevated bioavailable Cu in the water column immediately above the aft section of the wreck where the highest sedimentary load of Cu was located. Intermittently elevated concentrations of strong Cu-binding ligands occurred in this location, and their binding strength was consistent with ligands actively produced by organisms in response to Cu induced stress. The recruitment of benthic invertebrates was modified at the high-Cu location. Taxonomic groups usually considered robust to pollution were restricted to this site (e.g. barnacles) or were the most abundant taxa present (e.g. foraminifera). Our results demonstrate that Cu-contaminated sediments can impose a persistent point source of Cu pollution in high-energy reef environments, with the potential to modify the composition and recovery of biological communities.

Highly Stable, Coordinated Polymeric Nanoparticles Loading Copper(II) Diethyldithiocarbamate for Combinational Chemo/Chemodynamic Therapy of Cancer.

Disulfiram (DSF) has excellent in vitro anticancer activity in the presence of Cu(II). The anticancer mechanism studies have demonstrated that copper(II) diethyldithiocarbamate, Cu(DDC)2, is the crucial DSF's metabolite exhibiting anticancer activity. In this paper, highly stable polymeric nanoparticles were fabricated via a coordination strategy between Cu(II) and carboxylic groups in poly(ethylene glycol)- b-poly(ester-carbonate) (PEC) for efficient loading of Cu(DDC)2, which was generated by the in situ reaction of DSF and Cu(II). The properties of nanoparticles such as drug loading contents, sizes, and morphologies could be tuned by varying the feeding ratios of DSF, Cu(II), and PEC. These Cu(II)/DDC-loaded nanoparticles showed excellent stability in both neutral and weak acidic solutions and under dilution. In vitro anticancer study established that Cu(II)/DDC-loaded nanoparticles could enable a combination therapy of Cu(DDC)2-based chemotherapy and chemodynamic therapy mediated by bioavailable Cu(II) that was not in the form of Cu(DDC)2. The in vivo antitumor results demonstrated that the Cu(II)/DDC-loaded nanoparticles showed superior antitumor efficacy to DSF/Cu(II). Our study provided a facile and effective strategy of highly stable coordination-mediated polymeric nanoparticles for combinational therapy of cancer.

H2O and/or SO2 Tolerance of Cu-Mn/SAPO-34 Catalyst for NO Reduction with NH3 at Low Temperature

A series of molecular sieve catalysts (Cu–Mn/SAPO-34) with different loadings of Cu and Mn components were prepared by the impregnation method. The deNOx activity of the catalyst was investigated during the selective catalytic reduction (SCR) of NO with NH3 in the temperature range of 120 °C to 330 °C, including the effects of H2O vapors and SO2. In order to understand the poisoning mechanism by the injection of H2O and/or SO2 into the feeding gas, the characteristics of the fresh and spent catalyst were identified by means of Brunner−Emmet−Teller (BET), X-ray Diffraction (XRD), Scanning Electronic Microscopy (SEM) and Thermal Gravity- Differential Thermal Gravity (TG-DTG). The conversion of NO by the catalyst can achieve at 72% under the reaction temperature of 120 °C, while the value reached more than 90% under the temperature between 180 °C and 330 °C. The deNOx activity test shows that the H2O has a reversible negative effect on NO conversion, which is mainly due to the competitive adsorption of H2O and NH3 on Lewis acid sites. When the reaction temperature increases to 300 °C, the poisoning effect of H2O can be negligible. The poisoning effect of SO2 on deNOx activity is dependent on the reaction temperature. At low temperature, the poisoning effect of SO2 is permanent with no recovery of deNOx activity after the elimination of SO2. The formation of (NH4)2SO4, which results in the plug of active sites and a decrease of surface area, and the competitive adsorption of SO2 and NO should be responsible for the loss of deNOx activity over Cu/SAPO-34.

Cu-Promoted Cobalt Oxide Film Catalyst for Efficient Gas Emissions Abatement

Thin film catalysts have been recently reported as promising catalysts owing to their good catalytic activity and reduced material amount, leading to low-cost efficient catalysts for gaseous emissions control. Here, we report the slight loading of Cu in cobalt spinel using a one-step pulsed-spray evaporation chemical vapor deposition (PSE-CVD) synthesis technique for efficient short-chain volatile organic compounds (VOCs) emissions treatment. Crystalline structure and morphology analyses revealed nano-crystallite sizes and open-like morphology. The catalytic performance was evaluated through the complete oxidation of C3H6, as a short-chain representative model of VOCs, at a high gas hourly space velocity (GHSV). Very good activity was obtained towards the complete abatement of C3H6 at low temperature and no carbon monoxide (CO) was formed during the oxidation process. Slightly-promoted Co3O4 catalyst with Cu introduction resulted in high catalytic activity comparing to the performance of the catalysts in the literature, due to the high dispersion of Cu and high active surface oxygen amount. Moreover, to evaluate the capability of the used catalysts under near realistic reaction conditions, CO2 effect on the catalytic activity was performed and the catalyst exhibited very good results. Thus, the adopted slightly-doping strategy to tailor a high active catalyst at low temperature could establish a very promising route to strongly enhance the activity of such other catalysts towards gas emissions abatement at low temperature.

EVALUATION OF HEAVY METALS CONCENTRATION IN JAJARM BAUXITE DEPOSIT IN NORTHEAST OF IRAN USING ENVIRONMENTAL POLLUTION INDICES

Heavy metals are known as an important group of pollutants in soil. Major sources of heavy metals are modern industries such as mining. In this study, spatial distribution and environmental behavior of heavy metals in the Jajarm bauxite mine have been investigated. The study area is one of the most important deposits in Iran, which includes about 22 million tons of reserve. Contamination factor (CF), the average concentration (AV), the enrichment factor (EF) and geoaccumulation index (GI) were factors used to assess the risk of pollution from heavy metals in the study area. Robust principal component analysis of compositional data (RPCA) was also applied as a multivariate method to find the relationship among metals. According to the compositional bi-plots, the RPC1 and RPC2 account for 57.55% and 33.79% of the total variation, respectively. The RPC1 showed positive loadings for Pb and Ni. Also, the RPC2 showed positive loadings for Cu and Zn. In general, the results indicated that mining activities in the bauxite mine have not created serious environmental hazards in the study area except for lead and nickel. Finding potential relations between mining work and elevated heavy metals concentrations in the Jajarm bauxite mine area necessitates developing and implementing holistic monitoring activities.

Effects of Cu loading and zeolite topology on the selective catalytic reduction with C3H6 over Cu/zeolite catalysts

The objective of this study is to investigate the catalytic performance of Cu-zeolite catalysts supported on various types of zeolites (chabazite, MFI, and BEA) for selective catalytic reduction with C3H6. 2Cu/ZSM-5 exhibited a nearly 70% de-NOx performance at 360°C, Cu/SSZ-13 and Cu/BETA exhibited less than 60%. The loading of Cu also exhibited different de-NOx performances, which were related to the chemical states of Cu. The isolated Cu2+ ion was favorable to the NOx reduction compared to the bulk CuOx species. The effects of O2, CO2 concentrations and hydrothermal aging were investigated for the 2Cu/ZSM-5 catalyst.

Solid-state Synthesis of Composite Structures of Various Cu(I)-based Oxides with g-C3 N4 for Harvesting Solar Energy

Development of novel materials for an efficient harvesting of solar energy towards applications in environment and energy sectors is an important area of research. A metal-free polymeric material, g-C3 N4 is modified with three Cu(I)- based oxides namely Cu2 O, CuVO3 , and Cu3 VO4 to extend the absorption of the solar spectrum. The composite structures are synthesized by a facile one-step solid-state reaction under inter atmosphere and atmospheric pressure. The amounts of loadings of Cu(I)-based oxides onto g-C3 N4 is varied from 2 wt.% to 10 wt.%. Powder XRD patterns showed that the graphitic structure of carbon nitride is maintained upon the construction of hybrid structures with Cu(I) oxides. SEM images show the textural transformation of the bulk structure of g-C3 N4 into nanosheets upon thermal retreatment. FT-IR spectra further confirmed the stability of g-C3 N4 observed in the XRD patterns. In comparison with the pristine g-C3 N4 , the DR-UV-Vis spectra of the modified solid powders demonstrated a clear red shift in the absorption towards higher wavelength and their better prospects in harvesting solar energy. Tauc plots derived from the DR-UV-Vis spectra showed a narrowing of the direct-allowed band gap upon modifications with Cu(I)-based oxides. The composites showed moderate activity in photocatalytic degradation of rhodamine B under irradiation from a solar simulator

Heavy metal concentrations in water and sediment of the Steelpoort River, Olifants River System, South Africa

Steelpoort River has been adversely affected by human activities in the catchment. Water and sediment quality of the river was assessed in 2015. The concentrations of some of the metals in water were found to be high and exceeded the guideline values and the concentrations of metals in sediment were found exceeding the guideline values for Cr, Cu and Zn. The high concentrations of Cu and Zn at Site 1 and Site 2 (upstream) could have originated from anthropogenic sources, such as fertilisers and pesticides from discharge of agricultural wastes, whereas the high concentrations of Cr at Site 3, Site 4 (midstream) and Site 5 (downstream) could have originated from the mine waste, and from domestic/ industrial wastes respectively. The principal component analysis results showed two main components: PC-1 with high positive loading of Cu and Mn, and PC-2 with high positive loading of Zn. These findings indicate the presence of pollution. Therefore, control measures should be implemented to reduce river contamination from anthropogenic sources.

Heterogenized Cu (II) salen complex grafted on graphene oxide nanosheets as a precursing catalyst for the Pd‐free Sonogashira coupling

Cu (II) salen complex immobilized on graphene oxide nanosheets [Cu (II) salen@GO] was synthesized with 3‐chloropropyltrimethoxysilan as a linker and wholly characterized using various techniques like X‐ray diffraction, Fourier‐transform infrared, scanning electron microscopy/energy‐dispersive X‐ray spectroscopy, transmission electron microscopy, as well as atomic absorption spectroscopy (AAS). Cu (II) salen@GO as an effective heterogeneous catalyst has been investigated for the Sonogashira coupling reaction in dimethylsulfoxide with good to high yield (98%) in 4 hr at 110°C when the loading of Cu was 0.7 mmol g−1 based on Cu element analysis by AAS. It was understood that heterogeneous catalyst was as active as its homogeneous analog, and presented good recoverability and no significant loss in activity within successive runs.

Hybrid membranes with Cu(II) loaded metal organic frameworks for enhanced desulfurization performance

Abstract Tailoring the interface between the polymer matrix and filler to probe the structure-performance relationship is one of the critical research issues in hybrid membranes. In this study, metal organic framework (MOF) incorporated hybrid membranes are fabricated with polydimethylsiloxane (PDMS) as the matrix and Cu(II) loaded UiO-67-bpydc (bpydc refers to 2,2′-bipyridine-5,5′-dicarboxylic acid) as the filler, which are utilized for removing thiophene from model gasoline. The structure-performance relationship of the resultant membranes was investigated. The flux of the hybrid membrane shows a remarkable increase while avoiding obvious loss of selectivity. The loading of Cu(II) onto UiO-67-bpydc effectively tailors the interface between the polymer matrix and filler, which enhances the membrane separation performance. This study may offer a new example for designing MOF-based hybrid membranes towards efficient molecular separation.

Preparation of sulfated zirconia catalyst loaded by copper in nano-scale Green application to synthesis of biolubricant

This study investigates the activity of copper-doped catalysts supported on sulfated zirconia (SZ) for the esterification of Free Fatty Acid (FFA). Three catalysts SZ, Cu/SZ (sol) and Cu/SZ (imp) were prepared. The loaded catalysts contain 10% Cu supported on sulfated zirconia (Cu/SZ) were prepared by wet impregnation and sol-gel methods. The catalysts were characterized by X-ray diffraction, NH3 Temperature Programmed Desorption, N2 adsorption, Fourier transform infrared spectroscopy, and imaged by scanning electron microscopy. The XRD analysis showed that, the loading of Cu in the zirconia structure has stabilized the tetragonal zirconia phase, which is the most active phase. Also, the formation of (CuO-ZrO) composite has been proved. The TPD illustrated that the incorporation of Cu ions in the lattice of zirconia via sol-gel technique has lowered the acidity of the catalyst much more than impregnation technique. As a green application, different concentrations of the prepared catalysts were used for preparation of biolubricants by direct esterification of FFAs. The Cu/SZ/ (sol) catalyst has the highest activity. The percentage yields of synthesized biolubricants reached 99.8% when 0.3 % from the selected catalyst was utilized. Pour point, Flash point, Viscosity index, Apparent Viscosity and Percentage yield values of synthetic ester oils were evaluated.