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Wu Q.-H.,Shanghai Normal University | Wu Q.-H.,Key Laboratory of Resource Chemistry | Ren T.-R.,Shanghai Normal University | Ren T.-R.,Key Laboratory of Resource Chemistry
Guocheng Gongcheng Xuebao/The Chinese Journal of Process Engineering | Year: 2012

A new polymer ionic liquid catalyst PMHS-HEVIMBr was synthesized by four monomers of bromide 1-hydroxyethyl-3-vinyl imidazole (HEVIMBr), sodium methacrylate, 2-hydroxyethyl acrylate and styrene, and characterized in its structure. Then, the polymer ionic liquid was immobilized on the molecular sieve as solid catalyst particles for synthesis of ethylene carbonate (EC) via reaction of ethylene oxide (EO) with CO 2. The effects of reaction time, temperature, pressure, catalyst concentration on the EO conversion rate and EC selectivity were examined. The results indicated that 95% of EO conversion rate and 98% of EC selectivity could be reached at the optimal conditions of reaction time 4 h, pressure 2.5 MPa, temperature 403.15 K and mass ratio of catalyst to EO 9%. The catalyst activity remained stable after 10 times of recycle, EO conversion rate had no significant loss, EC selectivity was close to 100%. The kinetic equation on the catalytic reaction process was obtain, r=dC EO/dt=9.872× 10 4e -52.00/(RT)C EO. Source

Han L.,Shanghai Normal University | Liu J.,Key Laboratory of Resource Chemistry | Liu J.,Shanghai Normal University | Wang Z.,Shanghai Normal University | And 8 more authors.
CrystEngComm | Year: 2012

Monodisperse ZnSn(OH) 6 (ZHS) microcrystallites (MCs) with two morphologies have been prepared through a facile preparation method without complicated steps, or advanced experimental conditions or equipments. The morphology and compositional characteristics of the 3D hierarchitectures (HAs) of ZHS MCs were investigated by various techniques such as XRD, FESEM, TEM, UV-vis spectra, BET, XPS and EPR. In the reaction system the morphology evolution from cube to sphere was controlled by adding a different concentration of NH 4OH. Meanwhile, the formation mechanisms of the two ZHS MCs were studied via a series of time-dependent experiments. Interesting, ZHS MCs were self-assembled from irregular-shaped nanoparticles (5-10 nm). The XPS and EPR tests demonstrated oxygen vacancy defects existed in the ZHS MCs. The gas sensors based on ZHS presented a good sensor performance towards HCHO. However, the gas sensors based on of ZHS spherical MCs exhibited a higher response, shorter recovery time and good reproducibility towards HCHO than those of ZHS cubic MCs. More importantly, the best gas sensing properties were found coming from the ∼600 nm spherical ZHS MCs owing to more oxygen vacancy defects, lower band gap energy, and larger active surface area. © 2012 The Royal Society of Chemistry. Source

Wang F.,Shanghai Normal University | Wang F.,Key Laboratory of Resource Chemistry | Han R.,Shanghai Normal University | Han R.,Key Laboratory of Resource Chemistry | And 6 more authors.
Journal of Electroanalytical Chemistry | Year: 2013

A non-enzymatic hydrogen peroxide (H2O2) sensor has been developed based on the polydopamine (PDA)/silver nanoparticles (AgNPs) multilayer film (PDA/AgNPs)n modified glassy carbon electrode (GCE). The (PDA/AgNPs)n multilayer film was fabricated by alternatively dropping dopamine and silver ion solution on GCE taking advantages of the exceptional adhesive and reductive properties of self-polymerized PDA. Electrochemical property of (PDA/AgNPs)n modified GCE was characterized by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). Results showed that the as-constructed (PDA/AgNPs)n based sensor possesses encouraging catalytic ability for the reduction of H 2O2. The sensor has been employed to test real samples and shows strong potential in practical application. © 2013 Elsevier B.V. All rights reserved. Source

Liu J.,Key Laboratory of Resource Chemistry | Liu J.,Shanghai Normal University | Xu B.,Key Laboratory of Resource Chemistry | Xu B.,Shanghai Normal University | And 10 more authors.
CrystEngComm | Year: 2012

Nearly monodisperse NaY(MoO 4) 2 architectures with various shapes have been selectively prepared on a large scale by a capping agent free hydrothermal process using Y(OH) 3 nanorods as a precursor. The molar ratio of Na 2MoO 4/Y(OH) 3, the volume ratio of water/ethanol in the mixed solvents and temperature have comprehensive and crucial influences on the formation of multi morphologies of NaY(MoO 4) 2. The formation of multi morphologies is explained mainly from the viewpoint of the effective concentration of MoO 4 2- ions. At high temperature, high Na 2MoO 4/Y(OH) 3 ratio and high water/ethanol volume ratio, the effective concentration and reactivity of reactants, especially MoO 4 2- ions, are improved, which is beneficial to the growth of 3D NaY(MoO 4) 2 architectures. Under UV excitation, without further annealing treatment, NaY(MoO 4) 2:0. 05Eu 3+ bipyramid micro samples show strong red emission, corresponding to the characteristic lines of Eu 3+. © 2012 The Royal Society of Chemistry. Source

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