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https://www.readbyqxmd.com/read/29145134/comparative-analyses-of-catalytic-degradation-of-pcdd-fs-in-the-laboratory-vs-industrial-conditions
#1
Ming-Xiu Zhan, Jian-Ying Fu, Long-Jie Ji, Ivan Deviatkin, Sheng-Yong Lu
This study investigates the efficiencies and mechanisms of the catalytic degradation of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) first, in simulated laboratory conditions and then, in a commercial municipal solid waste incineration (MSWI) plant. Five commercially available V2O5-WO3/TiO2 (VWTi) catalysts were tested. The degradation efficiency of PCDD/Fs in the simulated flue gas ranged 22.8-91.7% and was generally higher than that in the MSWI flue gas of 8.0-85.4%. The degradation efficiency of PCDD/Fs in the real flue gas of the MSWI plant was largely hindered by the complex composition of the flue gas, which could not be completely reproduced in the simulated laboratory conditions...
October 24, 2017: Chemosphere
https://www.readbyqxmd.com/read/29145117/biodiesel-production-from-microbial-granules-in-sequencing-batch-reactor
#2
Lin Liu, Yuling Hong, Xin Ye, Lili Wei, Jie Liao, Xu Huang, Chaoxiang Liu
Effect of reaction variables of in situ transesterification on the biodiesel production, and the characteristic differences of biodiesel obtained from aerobic granular sludge (AG) and algae-bacteria granular consortia (AAG) were investigated. The results indicated that the effect of variables on the biodiesel yield decreased in the order of methanol quantity > catalyst concentration > reaction time, yet the parameters change will not significantly affect biodiesel properties. The maximum biodiesel yield of AAG was 66...
November 4, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/29145018/nitrogen-phosphorus-dual-doped-molybdenum-carbide-molybdenum-phosphide-carbon-nanospheres-for-efficient-hydrogen-evolution-over-the-whole-ph-range
#3
Jing-Qi Chi, Wen-Kun Gao, Jia-Hui Lin, Bin Dong, Kai-Li Yan, Jun-Feng Qin, Zi-Zhang Liu, Yong-Ming Chai, Chen-Guang Liu
MoO4(2-)@aniline-pyrrole (MoO4(2-)@polymer) spheres as precursors have been used to synthesize unique core-shell nanostructure consisting of molybdenum carbide and molybdenum phosphide composites encapsulated into uniformly dual N, P-doped carbon shells (Mo2C/MoP@NPC) through a facile two-step strategy. Firstly, porous core-shell N-doped Mo2C@C (Mo2C@NC) nanospheres have been synthesized with ultrafine Mo2C nanoparticles as core and ultrathin NC as shell by a annealing route. Secondly, Mo2C/MoP@NPC has been obtained maintaining intact spherical-like morphology through a phosphidation reaction in high temperature...
November 10, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/29144763/iron-catalyzed-indolizine-synthesis-from-pyridines-diazo-compounds-and-alkynes
#4
Tim Douglas, Anca Pordea, James Dowden
The iron(III)-catalyzed synthesis of indolizines from commercially available alkyne, pyridine, and diazo precursors is reported. This mild, expedient method is tolerant of various solvents and proceeds with as little as 0.25 mol % [Fe(TPP)Cl]. Significantly, this multicomponent reaction is compatible with electrophilic alkynes; control experiments demonstrate the importance of the catalyst in promoting pyridinium ylide formation over background reactivity.
November 16, 2017: Organic Letters
https://www.readbyqxmd.com/read/29144751/dendrimer-stabilized-metal-nanoparticles-as-efficient-catalysts-for-reversible-dehydrogenation-hydrogenation-of-n-heterocycles
#5
Christophe V Deraedt, Rong Ye, Walter Ralston, F Dean Toste, Gabor A Somorjai
Nanoparticles (Pd, Pt, Rh) stabilized by G4OH PAMAM dendrimers and supported in SBA-15 (MNPs/SBA-15 with M= Pd, Pt, Rh) were efficiently used as catalysts in the acceptorless dehydrogenation of tetrahydroquinoline/indoline derivatives in toluene (release of H2) at 130 °C. These catalysts are air stable, very active, robust, and recyclable during the process. The reverse hydrogenation reaction of quinoline derivatives (H2 storage) was also optimized and successfully performed in presence of the same catalysts in toluene at 60 °C under only 1 atmosphere of hydrogen gas...
November 16, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29144295/a-comparative-treatment-of-bleaching-wastewater-by-physicochemical-processes
#6
Ninad Oke, Swati Singh, Anurag Garg
The bleaching effluent discharged from a pulp and paper mill contains chlorinated organic compounds which are toxic to living matter. Physicochemical treatments such as coagulation and different advanced oxidation processes (AOPs) were employed for combined bleaching effluent generated from the first two stages (i.e. chlorination and alkali extraction) (pH = 3.5, chemical oxygen demand (COD) = 1,920 mg/L, and total organic carbon (TOC) = 663 mg/L). At optimum conditions (pH = 7.5, polyaluminium chloride (PAC) dose = 3...
November 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/29144293/facile-preparation-of-a-novel-catalytic-particle-electrode-from-sewage-sludge-and-its-electrocatalytic-performance-in-three-dimensional-heterogeneous-electro-fenton
#7
Baolin Hou, Renjian Deng, Bozhi Ren, Zhi Li
A novel type of catalytic particle electrode (SAC-Fe) was developed from sewage sludge and iron sludge via a facile method. The catalytic particle electrodes (CPEs) were also supposed to be heterogeneous catalyst for electro-Fenton (EF). The CPEs were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). SAC-Fe showed superior porous structure and higher adsorption capacity and catalytic activity than Fe3O4 magnetic nanoparticles. Catechol and total organic carbon (TOC) removal efficiency can reach 96...
November 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/29144281/preparation-of-rh-ag-bimetallic-nanoparticles-as-effective-catalyst-for-hydrogen-generation-from-hydrolysis-of-kbh4
#8
Liang Huang, Chengpeng Jiao, Liqiong Wang, Zili Huang, Feng Liang, Simin Liu, Yuhua Wang, Haijun Zhang, Shaowei Zhang
ISOBAM-104 protected Rh/Ag bimetallic nanoparticles (NPs) with average diameter less than 3.0 nm were synthesized by a co-reduction method. Ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and x-ray photoelectron spectroscopy (XPS) were employed to characterize the structure, particle size, and electronic structure of the prepared bimetallic NPs. The catalytic activities of prepared bimetallic NPs for hydrogen generation from hydrolysis of a basic KBH4 solution were evaluated in detail...
November 16, 2017: Nanotechnology
https://www.readbyqxmd.com/read/29144129/efficient-mechanochemical-synthesis-of-polyoxometalate%C3%A2-zif-complexes-as-reusable-catalysts-for-highly-selective-oxidation
#9
Xiaoxiao Zhao, Yunpeng Duan, Fei Yang, Wei Wei, Yanqing Xu, Changwen Hu
One-pot mechanochemical synthesis was demonstrated to be an efficient strategy to synthesize host-guest POM⊂rho-ZIF complexes (POM = polyoxometalate; rho-ZIF = zeolitic imidazolate framework with rho topology) with high crystallinity. In this work, the metastable rho-ZIF with large interior cavities and windows was used as host matrix for encapsulating and immobilizing bulky guest molecules with high loading efficiency and chemical stability. As novel catalysts, POM⊂rho-ZIF complexes were found effective for the selective oxidation of a series of sulfides to sulfoxides...
November 16, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/29144126/highly-active-carbene-potassium-complexes-for-the-ring-opening-polymerization-of-%C3%AE%C2%B5-caprolactone
#10
Mrinal Bhunia, Gonela Vijaykumar, Debashis Adhikari, Swadhin K Mandal
Herein we report the synthesis of two complexes of potassium employing strongly nucleophilic carbenes, such as cyclic "(alkyl)(amino)carbene (cAAC) and abnormal N-heterocyclic carbene (aNHC). Both complexes are dimeric in the solid state and the two potassium centers are bridged by trimethylsilylamide. In these complexes, the carbene- - -K interaction is predominantly electrostatic in character, which has been probed thoroughly by NBO and AIM analyses. Indeed, the delocalization energy of the cAAC lone pair calculated from the second-order perturbation theory was only 5...
November 16, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/29143834/cobalt-nickel-and-iron-complexes-of-8-hydroxyquinoline-di-2-picolyl-amine-for-light-driven-hydrogen-evolution
#11
Nadia Alessandra Carmo Dos Santos, Mirco Natali, Elena Badetti, Klaus Wurst, Giulia Licini, Cristiano Zonta
Novel cobalt, nickel, and iron complexes based on the pentadentate 8-hydroxyquinoline-di(2-picolyl)amine ligand were synthesized and thoroughly characterized. X-ray structures of both the cobalt and iron complexes were also obtained, showing the tendency to adopt a pseudo-octahedral geometry by coordination of an additional sixth ligand. These metal complexes were then studied as potential hydrogen-evolving catalysts (HECs) under both electrochemical and light-driven conditions. In particular, two different photochemical systems were tested involving either Ru(bpy)3(2+)/ascorbic acid or Ir(ppy)2(bpy)(+)/TEA sensitizer/sacrificial donor couples...
November 16, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29143627/conceptualizing-pathways-linking-women-s-empowerment-and-prematurity-in-developing-countries
#12
Patience A Afulani, Molly Altman, Joseph Musana, May Sudhinaraset
BACKGROUND: Globally, prematurity is the leading cause of death in children under the age of 5. Many efforts have focused on clinical approaches to improve the survival of premature babies. There is a need, however, to explore psychosocial, sociocultural, economic, and other factors as potential mechanisms to reduce the burden of prematurity. Women's empowerment may be a catalyst for moving the needle in this direction. The goal of this paper is to examine links between women's empowerment and prematurity in developing settings...
November 8, 2017: BMC Pregnancy and Childbirth
https://www.readbyqxmd.com/read/29143537/camphor-sulphonic-acid-mediated-quantitative-1-3-diol-protection-of-major-labdane-diterpenes-isolated-from-andrographis-paniculata
#13
Venu Sharma, Kamal K Kapoor, Debaraj Mukherjee, Vivek K Gupta, Manoj K Dhar, Sanjana Kaul
Phytochemical survey of the methanol extract of the dried aerial parts of Andrographis paniculata led to the isolation of major labdane diterpenes, namely 14-deoxy-11,12-didehydroandrographolide, andrographolide and neoandrographolide. Andrographolide was found to be the major phytoconstituent of the plant which was biologically active. For better physiochemical characteristics and bioefficacy, andrographolide is subjected to semi-synthetic modifications. However, presence of several free hydroxyl groups associated with this molecule make it quite polar and poorly soluble in many organic solvents and hence unsuitable for synthetic modifications...
November 16, 2017: Natural Product Research
https://www.readbyqxmd.com/read/29143527/origins-of-enantioselectivity-in-asymmetric-radical-additions-to-octahedral-chiral-at-rhodium-enolates-a-computational-study
#14
Shuming Chen, Xiaoqiang Huang, Eric Meggers, Kendall N Houk
The origin of asymmetric induction in the additions of carbon- and nitrogen-centered radicals to octahedral centrochiral rhodium enolates has been investigated with Density Functional Theory (DFT) calculations. Computed free energies of activation reproduce the preference for the experimentally observed major enantiomer. Good levels of enantioselectivity are maintained upon replacement of the bulky tert-butyl substituents on the ligands with methyl groups. Distortion-interaction analysis indicates that for both carbon-and nitrogen-centered radicals, which have relatively early and late transition states, respectively, the difference in the distortion energies controls the enantioselectivity...
November 16, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29143069/hemin-g-quadruplex-horseradish-peroxidase-mimicking-dnazyme-principle-and-biosensing-application
#15
Negar Alizadeh, Abdollah Salimi, Rahman Hallaj
Enzymes are macromolecular biological catalysts that accelerate chemical reactions. Enzyme labels are commonly used to obtain signal amplification in sensors and biosensors on the basis of reactions of some enzymes such as horseradish peroxidase (HRP). However, use of natural enzymes can encounter some challenges. Lately, nucleic acids that exhibit catalytic properties have attracted growing interest because they have certain advantages in comparison with traditional protein enzymes. DNAzymes are DNA-based catalysts, representing an important class of functional DNA, which have been widely used because of their excellent activity, programmability, signal amplification through catalytic turnover, high chemical stability, simple synthesis, and easy modification...
November 16, 2017: Advances in Biochemical Engineering/biotechnology
https://www.readbyqxmd.com/read/29143044/electrocatalytic-oxygen-evolution-with-a-cobalt-complex
#16
Hua-Tian Shi, Xiu-Xiu Li, Fang-Hui Wu, Wei-Bin Yu
The development of an earth-abundant, first-row water oxidation catalyst that operates at a high TOF and a low overpotential remains a fundamental chemical challenge. Cobalt complexes are important members of water oxidation catalysts. Herein, we report a cobalt-based robust homogeneous water oxidation catalyst, which can electrocatalyze water oxidation at a high pH and a low overpotential (η = 520 mV) in phosphate buffer. This homogeneous system exhibits a high turnover frequency (about 5 s(-1)) of catalyzing water oxidation to produce oxygen at η = 720 mV...
November 16, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29143032/reaction-monitoring-reveals-poisoning-mechanism-of-pd2-dba-3-and-guides-catalyst-selection
#17
Chiara Colletto, Jordi Burés, Igor Larrosa
We have discovered that the dba ligand in the commonly used Pd2(dba)3·CHCl3 cross-coupling pre-catalyst is susceptible to bis-arylation when used in the presence of aryl iodides. The in situ formed dbaAr2 ligands result in Pd-species with altered catalytic activity. In the case of study, the room temperature C3 arylation of benzo[b]thiophenes with aryl iodides, we have observed a marked catalyst deactivation when dba is arylated with electron-deficient aryl iodides, accounting for the poor yields obtained in the C3 arylation reactions with these aryl iodides...
November 16, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/29142789/catalytic-depolymerization-of-lignin-and-woody-biomass-in-supercritical-ethanol-influence-of-reaction-temperature-and-feedstock
#18
Xiaoming Huang, Ceylanpinar Atay, Jiadong Zhu, Sanne W L Palstra, Tamás I Korányi, Michael D Boot, Emiel J M Hensen
The one-step ethanolysis approach to upgrade lignin to monomeric aromatics using a CuMgAl mixed oxide catalyst is studied in detail. The influence of reaction temperature (200-420 °C) on the product distribution is investigated. At low temperature (200-250 °C), recondensation is dominant, while char-forming reactions become significant at high reaction temperature (>380 °C). At preferred intermediate temperatures (300-340 °C), char-forming reactions are effectively suppressed by alkylation and Guerbet and esterification reactions...
November 6, 2017: ACS Sustainable Chemistry & Engineering
https://www.readbyqxmd.com/read/29142616/scaling-relations-for-acidity-and-reactivity-of-zeolites
#19
Chong Liu, Ionut Tranca, Rutger A van Santen, Emiel J M Hensen, Evgeny A Pidko
Zeolites are widely applied as solid acid catalysts in various technological processes. In this work we have computationally investigated how catalytic reactivity scales with acidity for a range of zeolites with different topologies and chemical compositions. We found that straightforward correlations are limited to zeolites with the same topology. The adsorption energies of bases such as carbon monoxide (CO), acetonitrile (CH3CN), ammonia (NH3), trimethylamine (N(CH3)3), and pyridine (C5H5N) give the same trend of acid strength for FAU zeolites with varying composition...
October 26, 2017: Journal of Physical Chemistry. C, Nanomaterials and Interfaces
https://www.readbyqxmd.com/read/29142488/usefulness-of-a-nonsuture-closure-device-in-patients-undergoing-diagnostic-coronary-and-peripheral-angiography
#20
John T Owens, Shaun Bhatty, Robert J Donovan, Andrea Tordini, Peter Danyi, Kalpesh Patel, Jacob A Wegelin, Ion S Jovin
Vascular access site complications can follow diagnostic coronary and peripheral angiography. We compared the complication rates of the Catalyst vascular closure device, with the complication rates after manual compression in patients undergoing diagnostic angiographic procedures via femoral access. We studied 1,470 predominantly male patients undergoing diagnostic coronary and peripheral angiography. Catalyst closure devices were used in 436 (29.7%) patients and manual compression was used in 1,034 (70.3%) patients...
December 2017: International Journal of Angiology: Official Publication of the International College of Angiology, Inc
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