Fabrication of Ni/TiO2 visible light responsive photocatalyst for decomposition of oxytetracycline.

Nickel-impregnated TiO2 photocatalyst (NiTP) responding to visible light was prepared by the liquid phase plasma (LPP) method, and its photoactivity was evaluated in degrading an antibiotic (oxytetracycline, OTC). For preparing the photocatalyst, nickel was uniformly impregnated onto TiO2 (P-25) powder, and the nickel content increased as the number of LPP reactions increased. In addition, the morphology and lattice of NiTP were observed through various instrumental analyses, and it was confirmed that NiO-type nanoparticles were impregnated in NiTP. Fundamentally, as the amount of impregnated nickel in the TiO2 powder increased sufficiently, the band gap energy of TiO2 decreased, and eventually, the NiTP excited by visible light was synthesized. Further, OTC had a decomposition reaction pathway in which active radicals generated in OTC photocatalytic reaction under NiTP were finally mineralized through reactions such as decarboxamidation, hydration, deamination, demethylation, and dehydroxylation. In effect, we succeeded in synthesizing a photocatalyst useable under visible light by performing only the LPP single process and developed a new advanced oxidation process (AOP) that can remove toxic antibiotics.

H2 generation from steam gasification of swine manure over nickel-loaded perovskite oxides catalysts.

In this study, nickel-loaded perovskite oxides catalysts were synthesized via the impregnation of 10%Ni on XTiO3 (X = Ce, Sr, La, Ba, Ca, and Fe) supports and employed in the catalytic steam gasification of swine manure to produce H2-rich syngas for the first time. The synthesized catalysts were characterized using BET, H2-TPR, XRD, HR-TEM, and EDX analysis. Briefly, using perovskite supports resulted in the production of ultrafine catalyst nanoparticles with a uniform dispersion of Ni particles. According to the catalytic activity test, the gas yield showed the increment as 10% Ni/LaTiO3 < 10% Ni/FeTiO3 < 10% Ni/CeTiO3 < 10% Ni/BaTiO3 < 10% Ni/SrTiO3 < 10% Ni/CaTiO3. Meanwhile, zero coke formation was achieved due to the oxygen mobility of prepared catalysts. Also, the increase in the H2 production for the applied catalysts was in the sequence as 10% Ni/CeTiO3 < 10% Ni/FeTiO3 < 10% Ni/LaTiO3 < 10% Ni/BaTiO3 < 10% Ni/SrTiO3 < 10% Ni/CaTiO3. The maximum H2 selectivity (∼48 vol%) obtained by10% Ni/CaTiO3 was probably due to the synergistic effect of Ni and Ti on enhancing the water-gas shift reaction, and Ca on creating the maximum oxygen mobility compared to other alkaline earth metals doped at the A place of perovskite. Overall, this study provides a suitable solution for enhanced H2 production through steam gasification of swine manure along with suggesting the appropriate supports to prevent Ni deactivation by lowering coke formation at the same time.

Comparison of Pore Structures of Cellulose-Based Activated Carbon Fibers and Their Applications for Electrode Materials.

This study presents the first investigation of cellulose-based activated carbon fibers (RACFs) prepared as electrode materials for the electric double-layer capacitor (EDLC) in lieu of activated carbon, to determine its efficacy as a low-cost, environmentally friendly enhancement alternative to nanocarbon materials. The RACFs were prepared by steam activation and their textural properties were studied by Brunauer-Emmett-Teller and non-localized density functional theory equations with N2/77K adsorption isotherms. The crystallite structure of the RACFs was observed by X-ray diffraction. The RACFs were applied as an electrode material for an EDLC and compared with commercial activated carbon (YP-50F). The electrochemical performance of the EDLC was analyzed using galvanostatic charge/discharge curves, cyclic voltammetry, and electrochemical impedance spectroscopy. The results show that the texture properties of the activated carbon fibers were influenced by the activation time. Crucially, the specific surface area, total pore volume, and mesopore volume ratio of the RACF with a 70-min activation time (RACF-70) were 2150 m2/g, 1.03 cm3/g and 31.1%, respectively. Further, electrochemical performance analysis found that the specific capacitance of RACF-70 increased from 82.6 to 103.6 F/g (at 2 mA/cm2). The overall high specific capacitance and low resistance of the RACFs were probably influenced by the pore structure that developed outstanding impedance properties. The results of this work demonstrate that RACFs have promising application value as performance enhancing EDLC electrode materials.

Effective toluene oxidation under ozone over mesoporous MnOx/γ-Al2O3 catalyst prepared by solvent deficient method: Effect of Mn precursors on catalytic activity.

In this study, the role of manganese precursors in mesoporous (meso) MnOx/γ-Al2O3 catalysts was examined systematically for toluene oxidation under ozone at ambient temperature (20 °C). The meso MnOx/γ-Al2O3 catalysts developed with Mn(CH3COO)2, MnCl2, Mn(NO3)2.4H2O and MnSO4 were prepared by an innovative single step solvent-deficient method (SDM); the catalysts were labeled as MnOx/Al2O3(A), MnOx/Al2O3(C), MnOx/Al2O3(N), and MnOx/Al2O3(S), respectively. Among all, MnOx/Al2O3(C) showed superior performance both in toluene removal (95%) as well as ozone decomposition (88%) followed by acetate, nitrate and sulphated precursor MnOx/Al2O3. The superior performance of MnOx/Al2O3(C) in the oxidation of toluene to COx is associated with the ozone decomposition over highly dispersed MnOx in which extremely active oxygen radicals (O2-, O22- and O-) are generated to enhance the oxidation ability of the catalysts greatly. In addition, toluene adsorption over acid support played a vital role in this reaction. Hence, the properties such as optimum Mn3+/Mn4+ ratio, acidic sites, and smaller particle size (≤2 nm) examined by XPS, TPD of NH3, and TEM results are playing vital role in the present study. In summary, the MnOx/Al2O3 (C) catalyst has great potential in environmental applications particularly for the elimination of volatile organic compounds with low loading of manganese developed by SDM.

Decomposition of naproxen by plasma in liquid process with TiO2 photocatslysts and hydrogen peroxide.

Naproxen (NPX), one of the representative non-steroidal anti-inflammatory drug (NSAID) ingredients, was decomposed by plasma in liquid process (PiLP). Strongly oxidized species generated in the plasma field of the PiLP, such as OH radicals, were confirmed by optical emission spectroscopy Increasing the operation parameters (pulse width, frequency and applied voltage) of the power supply promoted plasma field generation and OH radical generation, and affected the NPX decomposition rate. Although the NPX decomposition reaction rate was improved by up to 18-30% by adding TiO2 photocatalyst powder and H2O2 to PiLP, but the optimal addition amount should be determined considering the plasma generation and scavenger effects. A decomposition pathway was proposed, in which NPX was mineralized into CO2 and H2O through five intermediates mainly by decarboxylation, demethylation, hydroxylation, and dehydration reactions via hydroxyl radicals.

Hydrogen Production through Catalytic Water Splitting Using Liquid-Phase Plasma over Bismuth Ferrite Catalyst.

This study examined the H2 production characteristics from a decomposition reaction using liquid-phase plasma with a bismuth ferrite catalyst. The catalyst was prepared using a sol-gel reaction method. The physicochemical and optical properties of bismuth ferrite were analyzed. H2 production was carried out from a distilled water and aqueous methanol solution by direct irradiation via liquid-phase plasma. The catalyst absorbed visible-light over 610 nm. The measured bandgap of the bismuth ferrite was approximately 2.0 eV. The liquid-phase plasma emitted UV and visible-light simultaneously according to optical emission spectrometry. Bismuth ferrite induced a higher H2 production rate than the TiO2 photocatalyst because it responds to both UV and visible light generated from the liquid-phase plasma.

Characteristics of hydrogen production by photocatalytic water splitting using liquid phase plasma over Ag-doped TiO2 photocatalysts.

Hydrogen production from water was investigated by applying liquid plasma (LPP) to photocatalytic splitting of water. The optical properties of LPP due to water emission were also evaluated. The correlation between the optical properties of plasma and the formation of active species in water was investigated with the photocatalytic activity of hydrogen production. TiO2 was also doped with Ag to evaluate the effect of enhancing photocatalytic activity. The photocatalytic activity was evaluated by the rate of hydrogen production, and the effect of hydrogen formation was also investigated by injecting methanol as an additive. As a result of examining the luminescence properties of LPP, it showed high luminescence in the 309 nm UV region and the 656 nm visible region. The hydrogen doping rate was increased in the Ag-doped TiO2 photocatalyst. Ag-doped TiO2 has wider light absorption into the visible region and narrower band gap. Due to these properties, the rate of hydrogen generation is superior to TiO2 photocatalysts. The photochemical reaction with LPP and photocatalyst in aqueous solution with CH3OH showed a significant increase in hydrogen production rate. The increase in hydrogen production by injection of additives is because the optical properties of generating OH radicals are improved and CH3OH is decomposed to act as an electron donor to improve hydrogen production.

Acid-treated waste red mud as an efficient catalyst for catalytic fast copyrolysis of lignin and polyproylene and ozone-catalytic conversion of toluene.

In this study, red mud (RM), a highly alkaline waste generated from alumina production industries, was used as a catalytic material for both fast copyrolysis of organosolv lignin (OL) and polypropylene (PP) and toluene removal under ozone at room temperature. The RM was pretreated with HCl to investigate the effect of alkalinity. In the catalytic fast copyrolysis of the OL and PP, the acid-treated RM (HRM) produced more aromatics, phenolics, and light olefins (C3 to C5) but less oxygenates and heavy olefins (C6 to C46) than the RM. The difference in pyrolytic performance between the RM and HRM was likely attributed to the concentrated Fe2O3 species in the HRM catalyst. In addition, more efficient toluene removal was observed over MnOx/HRM than over MnOx/RM owing to the large Brunauer-Emmett-Teller surface area, high amounts of Al and Fe, and optimal Mn3+/Mn4+ ratio. This study demonstrates that the RM, an industrial waste, can be reused as an effective catalytic material for not only biofuel production but also pollutant removal.

Enhanced bioaromatics synthesis via catalytic co-pyrolysis of cellulose and spent coffee ground over microporous HZSM-5 and HY.

Catalytic co-pyrolysis (CCP) of spent coffee ground (SCG) and cellulose over HZSM-5 and HY was characterized thermogravimetrically, and a catalytic pyrolysis of two samples was conducted using a tandem micro reactor that directly connected with gas chromatography-mass spectrometry. To access the more fundamental investigations on CCP, the effects of the zeolite pore structure, reaction temperature, in-situ/ex-situ reaction mode, catalyst to feedstock ratio, and the SCG and cellulose mixing ratio were experimentally evaluated. The temperature showing the highest thermal degradation rate of cellulose with SCG slightly delayed due to the interactions during the thermolysis of two samples. HZSM-5 in reference to HY produced more aromatic hydrocarbons from CCP. With respect to the reaction temperature, the formation of aromatic hydrocarbons increased with the pyrolytic temperature. Moreover, the in-situ/ex-situ reaction mode, catalyst/feedstock, and cellulose/SCG ratio were optimized to improve the aromatic hydrocarbon yield.

Degradation of dimethyl phthalate using a liquid phase plasma process with TiO2 photocatalysts.

The liquid phase plasma (LPP) method with a TiO2 photocatalyst and hydrogen peroxide was used to decompose dimethyl phthalate (DMP). As the applied voltage, pulse width, and frequency were increased, the rate of decomposition was increased and the decomposition rate was 63% for 180 min under plasma optimum conditions. The addition of TiO2 photocatalyst and hydrogen peroxide increased the DMP decomposition reaction rate, but an excess cause a decrease in decomposition rate due to a decrease in conductivity, blocking of ultraviolet light, and scavenger effect. When the TiO2 photocatalyst and hydrogen peroxide were used together, the decomposition reaction rate of DMP was greatly improved by using LPP single process alone. Also, when all the processes were used at the same time, the decomposition reaction rate was improved to about 2.8 times. DMP undergoes bond cleavage and ultimately decomposes into CO2 and H2O via dimethyl 4-hydroxyphthalate and methyl salicylates due to hydroxyl radicals and various active species generated by the LPP reaction.

Production of an upgraded lignin-derived bio-oil using the clay catalysts of bentonite and olivine and the spent FCC in a bench-scale fixed bed pyrolyzer.

Lignocellulosic biomass is an abundant renewable energy source that can be converted into various liquid fuels via thermochemical processes such as pyrolysis. Pyrolysis is a thermal decomposition method, in which solid biomass are thermally depolymerized to liquid fuel called bio-oil or pyrolysis oil. However, the low quality of pyrolysis oil caused by its high oxygen content necessitates further catalytic upgrading to increase the content of oxygen-free compounds, such as aromatic hydrocarbons. Among the three different types of lignocellulosic biomass components (hemicellulose, lignin, and cellulose), lignin is the most difficult fraction to be pyrolyzed because of its highly recalcitrant structure for depolymerization, forming a char as a main product. The catalytic conversion of lignin-derived pyrolyzates is also more difficult than that of furans and levoglucosan which are the main pyrolysis products of hemicellulose and cellulose. Hence, the main purpose of this study was to develop a bench-scale catalytic pyrolysis process using a tandem catalyst (both in-situ and ex-situ catalysis mode) for an efficient pyrolysis and subsequent upgrading of lignin components. While HZSM-5 was employed as an ex-situ catalyst for its excellent aromatization efficiency, the potential of the low-cost additives of bentonite, olivine, and spent FCC as in-situ catalysts in the Kraft lignin pyrolysis at 500 °C was investigated. The effects of these in-situ catalysts on the product selectivity were studied; bentonite resulted in higher selectivity to aromatic hydrocarbons compared to olivine and spent FCC. The reusability of HZSM-5 (with and without regeneration) was examined in the pyrolysis of lignin mixed with the in-situ catalysts of bentonite, olivine, and spent FCC. In the case of using bentonite and spent FCC as in-situ catalysts, there were no obvious changes in the activity of HZSM-5 after regeneration, whereas using olivine as in-situ catalyst resulted in a remarkable decrease in the activity of HZSM-5 after regeneration.

Removal of toluene using ozone at room temperature over mesoporous Mn/Al2O3 catalysts.

The catalytic oxidation of toluene with ozone at room temperature was carried out over hierarchically ordered mesoporous catalysts (CeO2 (meso), Mn2O3 (meso), ZrO2 (meso), and γ-Al2O3 (meso)) and Al2O3 with various textural properties and phases (γ-Al2O3 (meso), γ-Al2O3 (13 nm), and α-Al2O3) to examine the effects of the nature of the catalyst on the catalytic activity. The catalysts were characterized by N2-physisorption measurements, powder X-ray diffraction, temperature programmed reduction, X-ray photoelectron spectroscopy and scanning transmission electron microscopy with energy dispersive spectroscopy. Among the ordered mesoporous catalysts, γ-Al2O3 (meso) had the highest toluene removal efficiency because of its highest surface area and pore volume, which in turn was selected for further investigation. Manganese (Mn) was introduced to various Al2O3 to improve the toluene removal efficiency. Comparing the Mn-loaded catalysts supported on various Al2O3 with different crystalline phases or pore structures, Mn/γ-Al2O3 (meso), had the highest catalytic activity as well as the highest CO2/CO ratio. The higher activity was attributed to the larger surface area, weaker interaction between Mn and Al2O3, and larger portion of Mn2O3 phase. The increase in ozone concentration led to an improvement in the carbon balance but this enhancement was insufficient due to the deposition of by-products on the catalyst. After long term tests at room temperature, the reaction intermediates and carbonaceous deposits of the used catalysts were identified.

Preparation and Characterization of Bimetallic Fe-Ni Oxide Nanoparticles Using Liquid Phase Plasma Process.

The Fe-Ni oxide bimetallic nanoparticles (FNOBNPs) were synthesized in the liquid phase plasma (LPP) method employed an iron chloride and nickel chloride as metal precursors. The sphericalshaped FNOBNPs were synthesized by the LPP process and, the size of particles was growing along with the progression of LPP reaction. The synthesized FNOBNPs were comprised of Fe3O4 and NiO. Iron had a higher reduction potential than nickel and resulted in higher iron composition in the synthesized FNOBNPs. The control of molar ratio of metal precursors in initial reactant solution was found that it could be employed as a means to control the composition of the elements in FNOBNP.

Facile Synthesis of Chromium Oxide on Activated Carbon Electrodes for Electrochemical Capacitor Application.

Chromium oxide/carbon nanocomposites (COCNC) were synthesized by using a liquid phase plasma process, and the electrical properties of the supercapacitor electrode were investigated. Spherical chromium oxide (Cr2O3) nanoparticles with the size of 100-150 nm were dispersed uniformly on activated carbon powder surface. The quantity of chromium oxide nanoparticle precipitate increased with increasing LPP reaction time and the specific capacitance of COCNC increased with increasing LPP reaction time.

H2 Production from Yellow Poplar Gasification Over Ni/Spent FCC.

Ni/spent FCC catalyst was applied as the catalyst on the catalytic pyrolysis and gasification of yellow poplar (YP). Larger amount of gas (CO, CO2, H2, C1~C4) was produced by applying Ni/spent FCC catalyst to the catalytic pyrolysis and gasification of YP. Ni/spent FCC catalyst also increased the selectivity of phenols and aromatic hydrocarbons in oil product during the pyrolysis and gasification of YP. Overall catalytic performance of Ni/spent FCC catalyst was similar level with that of Ni/γ-Al2O3, suggesting its potential use.

ErbB4/KITENIN-Mediated Signaling is Activated in Cetuximab-Resistant Colorectal Cancer Cells.

ErbB4/KITENIN signaling plays a role in epidermal growth factor receptor (EGFR)-independent EGF pathways mediating the invasiveness and tumorigenesis of colorectal cancer cells. However, whether alterations in ErbB4/KITENIN signaling play a role in the resistance to anti-EGFR therapy remains unclear. Here, we established cetuximab-resistant DLD1 and HT29 cells, and analyzed changes in ErbB4/KITENIN signaling. c-Jun, a final effector in ErbB4/KITENIN-mediated signaling, was upregulated, whereas KITENIN levels remained constant in both cetuximab-resistant cell lines. The phosphorylation of EGFR and ErbB4 was increased in cetuximab-resistant cells, suggesting that ErbB4/KITENIN signaling contributed to the acquisition of cetuximab resistance in the cells. Silencing of KITENIN and/or ErbB4 increased cetuximab sensitivity in cetuximab-resistant cells. This study is the first to report the activation of ErbB4/KITENIN-mediated signaling in cetuximab-resistant colorectal cancer cells and the potential clinical application of ErbB4/KITENIN-targeting therapy for overcoming anti-EGFR resistance.

Decyl Glucoside Synthesized by Direct Glucosidation of D-Glucose Over Zeolite Catalysts and Its Estrogenicity as Non-Endocrine Disruptive Surfactant.

The estrogenicity of decyl glucoside was asserted as a non-endocrine disruptive surfactant with its preparation method using zeolite catalysts. Its estrogenicity was estimated using E-assay method. The decyl glucoside was synthesized by direct glucosidation from D-glucose with 1-decanol. The conversion and yield were improved with increasing of amount of acid sites of the zeolite catalysts. The decyl glucopyranoside is more hydrophilic than nonylphenol and has a high wettability. The decyl glucopyranosides exhibited extremely lower proliferation of estrogenic cell compared with nonylphenol.

Catalytic Performance of Supported Pd Catalyst Prepared with Different Palladium Precursors for Catalytic Combustion of BTH.

Catalytic combustion of benzene, toluene, and hexane (BTH) was carried out to investigate in this study the effect of palladium precursor on the property and performance of 1 wt.% Pd/γ-Al2O3. Properties were characterized by X-ray diffraction (XRD), Brunauer Emmett Teller (BET) surface area, temperature programmed reduction (TPR), Transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analyses. When palladium precursor was used to prepare the catalyst, it had a great effect on the property and performance of the supported palladium catalyst. Total acidity, size of palladium particle, and oxidation state of palladium were associated with catalytic activity of the catalyst. Higher total acidity of the catalyst and larger particle size of palladium favorably affected the catalytic activity. In addition, palladium species with high oxidation state might be useful to increase catalytic activity in BTH combustion.

In-Situ Catalytic Pyrolysis of Waste Lignin Over Desilicated Beta.

Desilicated Beta (DeBeta) was applied as the catalyst to the catalytic pyrolysis of waste lignin for the formation of aromatic hydrocarbon, and its performance was compared with that of the unmodified Beta. Large amounts of oxygen containing pyrolyzates were efficiently converted to stable aromatic hydrocarbons over both Beta and DeBeta catalysts. Compared to Beta, DeBeta exhibited the higher performance for the formation of aromatic hydrocarbons due to the enhanced diffusion efficiency through the mesopore.

Enhanced stability of bio-oil and diesel fuel emulsion using Span 80 and Tween 60 emulsifiers.

Bio-oil (biomass pyrolysis oil) has some undesirable properties (e.g., low heating value, high corrosiveness, and high viscosity) that restrain its direct use as a transportation fuel. The emulsification of bio-oil and diesel is an effective and convenient method to use bio-oil in the present transportation fuel infrastructure. The addition of an emulsifying agent (emulsifier or surfactant) to two immiscible liquids of diesel and bio-oil is an important step in emulsification. The hydrophilic-lipophilic balance (HLB) value, according to the chemical structure and characteristics of the emulsifier, is a key parameter for selecting a surfactant. In this study, an ether treatment of raw bio-oil was carried out to separate the ether-soluble fraction of bio-oil from its heavy (dark brown and highly viscous) fraction, and the ether-extracted bio-oil (EEO) was processed further for emulsification into diesel fuel. The effects of the HLB value of the emulsifier and the contents of EEO, diesel, and emulsifier on the stability of the EEO/diesel emulsion were investigated. To optimize the HLB value of the emulsifier, different HLB values (4.3-8.8), which were prepared by mixing different amounts of Span 80 and Tween 60 as surfactants, were used for the EEO and diesel emulsification. A HLB value of 7.3 with diesel, EEO, and emulsifier contents of 90, 5, 5 wt%, and 86, 7.4, 6.6 wt% resulted in EEO/diesel emulsions (without phase separation) stable for 40 and 35 days, respectively. Measurement of the high heating value (HHV) of the emulsified fuels gave a 44.32 and 43.68 MJ/kg values for the EEO to emulsifier mass ratios of 5:5 and 7.4:6.6, respectively. The stability of emulsified EEO and diesel was verified by TGA and FT-IR methods.