heteropolyacids as catalysts for mtbe synthesis

... acid) was collected as IRMOF-8 - Purple cubic crystals (25% based on benzimidazole) was collected as ZIF-9 - Deep purple crystals (88% based on 1,3,5-benzenetricarboxylic acid) was collected as MOF-199 ... precursors has been widely employed in the synthesis of pyrrole, pyrazoles, and their derivatives as important intermediates for pharmaceutical and fine chemical industry, as well as for the development ... catalyst loading were required for the same reaction However, the ZIF-9 was slightly less active for the Knoevenagel condensation as compared to some solid base catalysts such as amine-functionalized...

Ngày tải lên: 10/05/2014, 21:59

... nitrogen physisorption measurements  It is first time to use these Cu-MOFs as heterogeneous catalysts for the reactions: i) the Cu3 (BTC)2 was used as a heterogeneous catalyst for the direct oxidative ... crystals were formed 2.3.3 Synthesis and characterization of Cu (BPDC)2 (BPY)  The synthesis yield was approximately 66% based on H2 BPDC  The copper component in Cu2 (BPDC)2 (BPY) was 18% (ICP-MS) ... (BPY) 2.3.4 Synthesis and characterization of Cu(BDC)  The synthesis yield was approximately 66% based on H2 BDC  The copper content in the Cu(BDC) was 29% (ICP-MS)  Langmuir surface areas of 616...

Ngày tải lên: 18/06/2015, 17:07

... dioxide from flue gas, synthesis gas and other industrial gases by chilling and pressurizing the exhaust or by passing the fumes through a fluidized bed of aqueous base solution was significantly ... research in this area [20] The number of publications on MOFs as catalysts was significantly lower than the case of MOFs as adsorbents for gas capture and storage CHAPTER LITERATURE REVIEWS 1.1 Metal ... that there are some basic approaches to design heterogeneous catalysts based on MOFs such as supports for an active metal, bringing ligands as an active site, inorganic node as an active site,...

Ngày tải lên: 20/05/2016, 15:58

... crystallization of the salt Therefore, residual amount of water was always available in the salt as well as in the as- received anhydrous EG No extra distillation was carried out to remove the residual ... atmosphere) for more than h inside the glove box Care was taken to ensure that no external water was added during the experiments In effect, the salt, glass wares and the electrodes were vacuum dried before ... source of water As the nanotubes formation was not uniform in the

Ngày tải lên: 19/03/2014, 16:48

... esterases or lipases In general, esterases from microorganisms or animal sources (such as the integration of biotransformations into catalyst Pseudomonas putida esterase or pig liver esterase, ... catalysts has very little to offer for the catalysis of Diels±Alder (and the reverse) reactions (Diels±Alderases)[139] For this reason one of the intriguing areas of biomimickry, namely the formation ... Historically, the asymmetric synthesis of epoxides derived from electronpoor alkenes, for example a, b-unsaturated ketones, has not received as much attention as the equivalent reaction for electron-rich...

Ngày tải lên: 09/05/2014, 17:00

... observed in the gas phase The intact chemical composition of the QC was not observed, as typical of the spectra of thiolated clusters [34,38] AgnSm- species observed in the gas phase are dissociation ... dissociation products as well as gas phase reaction products Intact clusters, along with the monolayers, are seen only in MALDI-MS and ESI-MS of the free clusters [34] One of the interesting aspects of ... Nanoparticles as Catalysts for Selective Hydrogenation of α, βUnsaturated Ketones and Aldehydes Angew Chem Int Ed 2010, 49:1295 12 Haruta M, Yamada N, Kobayashi T, Iijima S: Gold catalysts prepared...

Ngày tải lên: 21/06/2014, 05:20

... observed for a deposition time of 30 min, as shown in Fig 2a The diamond crystallite size increased proportionally for a deposition time of h, and lateral collision of growing particles began forming ... region) A fast Fourier transform analysis was employed to measure the spacing between the atomic planes, which were found to vary The lattice spacing in different regions was measured to be 1.1, 1.16, ... nucleation centers for subsequent growth [31] Thus the formation of a dense amorphous carbon phase is a plausible route for nucleating diamond The iron nanoparticle may act as catalyst in decomposing...

Ngày tải lên: 21/06/2014, 22:20

... with, the production of silanols is useful as they are widely employed for the production of silicon-based polymers as well as intermediates in organic synthesis [77-78] Transition metal catalyzed ... and alcoholysis are also important for the production of hydrogen gas Hydrogen gas that was produced can be used as a reactant in organic syntheses, specifically for hydrogenation reactions [87-88] ... more easily using common spectroscopic techniques, such as Mass Spectrometry, Nuclear Magnetic Resonance (NMR) or Fourier Transformed Infra-Red (FTIR) spectroscopy This methodology thus allows for...

Ngày tải lên: 09/09/2015, 18:57

... 2.2.1.4 Gas-phase deposition method Gas-phase deposition method has also been used to prepare hydrogenation catalysts A systematic comparative study of preparing catalysts via gas phase deposition ... on oxides For fine chemicals 11 Chapter Literature Review manufacture activated carbon is the most common support material Aluminas and silicas as well as CaCO3 or BaSO4 are preferred for special ... cinnamaldehyde hydrogenation was performed by Lashdaf et al (2003) Small Pd metal crystallites were formed by gas-phase deposition method even with high metal loadings, whereas larger Pd particles were...

Ngày tải lên: 11/09/2015, 10:18

... heterogeneous catalysts Successful performance of Cu/ZnObased catalysts, ionic liquid-based catalysts, and metal oxidesbased catalysts for CO2 utilization has been reported in this review; nevertheless, ... surface areas decreased when the metal contents increased In the case of Cu and Au, the addition of large amounts of CuO and AuO led to the formation of large pore diameter of catalysts in contrast ... 3.2.2 Supported mesoporous catalysts The use of mesoporous materials as supports, such as MCM-41 for cyclic carbonates synthesis from CO2 and epoxides has been reported as well [40,66,67] The combination...

Ngày tải lên: 08/10/2015, 23:14

... hydrotalcites being used as catalyst for synthesis of biodiesel has been provided by Helwani et al [1] and Zabeti et al [3] Hydrotalcites/LDH has been used as catalyst as well as support for exogenous catalytic ... strong Lewis basic sites associated with O2ÀMn+ acid–base pairs Basic sites associated with structural hydroxyl groups and strong Lewis basic sites associated with O2ÀMn+ acid– base pairs are ... as a solid base catalyst Fuel 2008;87:216–21 [20] Albuquerque MCG, Urbistondo IJ, González JS, Roble JMM, Tost RM, Castellón ER, et al CaO supported on mesoporous silicas as basic catalysts for...

Ngày tải lên: 08/10/2015, 23:24

... agreement, which has it that ‘Learners’ motivation makes teaching and learning immeasurably easier and more pleasant, as well as more productive’ In the book entitled ‘Expectations about classrooms’, ... survey was feasible in the form of interviews, in which the writer would confer with other teachers from Hanoi School for Foreign Language Gifted Students about their experiences as well as opinions ... classroom, the outlined qualities seem relevant and justified as far as a given classroom is concerned commonly For a more detailed understanding of the roles of the teacher in language classroom,...

Ngày tải lên: 07/09/2013, 13:06

... as good when osteogenesis was less than two-thirds with no reconstruction required All other results were graded as poor Forty cases were judged as excellent, 17 cases as good, and 10 cases as ... under general anesthesia before skin incision The P(LA/CL) tube serving as a scaffold for the cells was the same as used for dogs Twenty-three tissueengineered conduits for extracardiac total cavopulmonary ... vs TEVAs at months, ‡‡ P < 0.01 vs TEVAs at months 12M (b) Stiffness/width was calculated as stiffness (mN/mm) = elastic modulus (mN/mm2) × wall thickness (mm) P < 0.01 *P < 00.05 vs TEVAs at...

Ngày tải lên: 25/10/2013, 08:20

... communication between people Speech synthesis, automatic generation of speech waveforms, has been under development for several decades Recent progress in speech synthesis has produced synthesizers with ... mechanism which takes phrase and accent information as input and produces a continuous F0 contour as output The input to the mechanism is in the form of impulses, used to produce phrase shapes, and step ... or unvoiced properties, aspirate or non-aspirate, nasal or non-nasal and the place of consonant in syllable Based on these features, Vietnamese consonants can be arranged as Table 2.3 Table 2.3:...

Ngày tải lên: 19/02/2014, 08:58

... (micromolar) affinity As the bioassays on state, whereas [A10L]PnIA stabilizes a desensitized state fish and insects as well as intracranial injections into rats which, in the case of the a7[L247] ... caused an increase in potency as arise primarily from a3b2 and a3b4 nAChRs Activity on well as a shift in selectivity: while PnIA inhibited an a-BTXa7 nAChRs was excluded for two reasons: (a) EpI ... [21], as well as pharmacological studies such as those shown in (B) In slices, an a7* nAChR on adjacent glutamate terminals was found to indirectly influence dopamine release via the release of...

Ngày tải lên: 19/02/2014, 12:20

... 0.25 °CÆmin)1 was therefore preferred for subsequent experiments with GT TFOs Padlock formation with TC oligonucleotides The use of TC TFOs has not been previously described for the formation of ... DNA ligase buffer (New England Biolabs) with 10 U T4 polynucleotide kinase for h at 37 °C Synthesis of the triplex stabilizing agent BQQ has been described previously [29] Plasmids Plasmids pY, ... 5350 Cleveland, OH, USA) (1 U for XmnI, 12 U for DraIII, 2.5 U for XbaI) and incubating for h at 37 °C Phosphatase was inactivated for 20 at 65 °C DNA was then ethanol precipitated and resuspended...

Ngày tải lên: 20/02/2014, 03:20

... substrate As for the mammalian l-gulono-1,4lactone oxidases [26], the temperature optimum for the dehydrogenase reaction was relatively high (39 °C) (Fig 4B) Preincubation at 60 °C for resulted ... dehydrogenases ⁄ oxidases in other bacterial genomes, we used the rat l-gulono-1,4-lactone oxidase as a query sequence in blast searches of the protein database These searches retrieved, for a limited ... the mycobacterial enzyme, as observed for the plant l-galactono-1,4-lactone dehydrogenase [12,25] No dehydrogenase activity could be measured in the presence of mm potassium cyanide Mg2+ and Ca2+...

Ngày tải lên: 07/03/2014, 12:20

... reductase [29] and a weak competitive inhibitor for methylmalonyl-CoA mutase [44] 2¢-DeoxyAdoCbl is 31%, 17%, and 5–13% as active as AdoCbl for diol dehydratase [38,45], glycerol dehydratase [41], ... 302 400 m)1Æcm)1 for diol dehydratase and ethanolamine ammonia-lyase, respectively Based on the predicted molecular masses, e1%,280 was calculated to be 5.81 and 6.21 for the former and latter ... than that for AdoCbl was used, low but distinct coenzyme activity was observed with AdoMeCbl As shown in Table 1, its kcat value was about 0.27% that for AdoCbl, and the rate of mechanism-based inactivation...

Ngày tải lên: 07/03/2014, 21:20

... the basis for the rearrangement of the actin cytoskeleton by bacterial effectors like Salmonella invasion protein A (SipA) and C (SipC) Whereas SipA decreases the critical concentration for F-actin ... Arg–ADP-ribose bond in actin, which was catalyzed by C2 toxin, was cleaved by hydroxylamine, this was not the case for the ADP-ribose bond to actin catalyzed by TccC3 Mass spectrometric analysis of ... not accept polymerized actin as substrate [68] Actin as target for toxin modification Aeromonas salmonicida is a fish pathogen which produces the bifunctional Aeromonas exotoxin T (AexT) [69,70]...

Ngày tải lên: 14/03/2014, 22:20