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45 results on '"Gu, Zhenggui"'

27. Study on Catalytic Synthesis of Low Molecular Weight Polyether Polyol by Composite Alkaline Earth Metal

Author

Wang Can, Li Shuo, Gu Zhenggui, Yacheng Liu, Cao Xiaoyan, and Kaijun Wang

Subjects
chemistry.chemical_classification, Alkaline earth metal, Chemical engineering, Polyol, Chemistry, Composite number, Catalysis
Abstract

Polyether Polyol is one of the main intermediates in the synthesis of polyurethane. This research work investigated the optimization of polyether polyol from propylene oxide using Single Factor Experiments and Response Surface Methodology (RSM) through composite alkaline earth metal catalyst (BaO/MgO/γ-Al2O3). The BaO/MgO/γ-Al2O3 catalyst was prepared with alkaline earth metal oxide immobilized on γ-Al2O3 by co-precipitation method. The preparation conditions of the catalysts is calcination temperature=600 °C, n(Ba):n(Al)=0.1:1, n(Mg):n(Al)=0.3:1. Represented with XRD, SEM, BET, CO2-TPD, etc. Characterization results showed that the catalysts indicated strong basic site, perfect particle surface area, pore volume, pore size and relatively uniform particle size distribution. Batch analyses demonstrated that the polyether molecular weight and the epoxide conversion was highly influenced by different process factors which include reaction temperature, pressure, time and the amount of catalyst. The conversion of propylene oxide and molecular weight to target product reached almost 63.5% and 600, respectively under the conditions of reaction temperature 190 °C, pressure 2 MPa, time 6 h and catalyst dosage 6%.

Published
2020

34. Lewis acid-oxygen vacancy interfacial synergistic catalysis over SO42−/Ce0.84Zr0.16O2–WO3–ZrO2for N,N-diethylation of aniline with ethanol

Author

Liu, Yacheng, Mao, Qifan, Cao, Xiaoyan, Huang, Xin, Wang, Kaijun, Wang, Can, Li, Shuo, and Gu, Zhenggui

Abstract

Herein, a new mechanism involving Lewis acid-oxygen vacancy interfacial synergistic catalysis for aniline N,N-diethylation with ethanol was proposed, and the SO42−/Ce0.84Zr0.16O2–WO3–ZrO2catalyst (SCWZ) with both Lewis acid sites and oxygen vacancies was synthesized by the hydrothermal method, which shows better catalytic activity than the reported solid acidic catalysts. Besides, the SO42−/ZrO2(SZ) and SO42−/WO3–ZrO2(SWZ) catalysts were also prepared and compared with SCWZ to investigate the synergistic effect of each component. The SO42−and WO3mainly generate Lewis acid by bonding with ZrO2, which is beneficial for the fracture of the N–H bond in aniline. The Ce0.84Zr0.16O2solid solution mainly plays a vital role in generating the oxygen vacancies as the interface active species, which can participate in stripping –OH from ethanol, then the carbocation will also be released, which only needs 1.3805 kcal/mol energy, calculated by density functional theory (DFT), to be input. In comparison, the traditional reaction mechanism needs the Brønsted acidic sites to promote the protonation of ethanol, then dehydration and subsequent formation of carbocation followed, and 108.6846 kcal/mol energy needs to be input, which is far higher than that of the new mechanism. The apparent activation energy (Ea) over SCWZ was measured by experiment to be 34.09 kJ/mol, which is much lower than that of SWZ (47.10 kJ/mol) and SZ (54.37 kJ/mol), illustrating comparatively preferable kinetics for SCWZ than that of SWZ and SZ. Besides, the conversion of aniline and selectivity to N,N-diethylaniline over SCWZ reach almost 100% and 73%, respectively. The SCWZ can be renewed for 4 times without rapid deactivation, and the longevity of SCWZ is longer than that of SWZ and SZ, as the loaded SO42−and tetragonal ZrO2are stabilized by Ce0.84Zr0.16O2and WO3, respectively.

Published
2020
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35. Preparation and characterization of Zr(SO4)2/TiO2 catalyst

Author

Huang Xin, Sun Hao, and Gu Zhenggui

Subjects
Titanium, Zirconium, Materials science, Sulfates, 020209 energy, Biomedical Engineering, Biophysics, chemistry.chemical_element, Bioengineering, 02 engineering and technology, General Medicine, Solid acid, Catalysis, Characterization (materials science), law.invention, Biomaterials, chemistry, Chemical engineering, law, 0202 electrical engineering, electronic engineering, information engineering, Calcination
Abstract

Solid acid Zr(SO4)2/TiO2 catalyst has highly catalytic activity, and has non-corrosiveness to equipment. It is separated from production expediently. As the above advantages, the influence of Zr(SO4)2 loading amount, calcination temperature, and calcination time on the solid acid Zr(SO4)2/TiO2 catalyst preparation process is discussed. The experimental condition is optimized by orthogonal test, the result indicate that Zr(SO4)2 load is 65%, calcination temperature is 430°C, and calcination time is 2.5 h. Solid acid catalyst Zr(SO4)2/TiO2 is analyzed and characterized by FT-IR, XRD and SEM. The results will provide the experimental condition for enlarging experimental study.

Published
2016

38. Evaluation of bacterial biodegradation and accumulation of phenanthrene in the presence of humic acid.

Author

Gu, Zhenggui, Gu, Minfen, He, Chang, Zhang, Jie, Xie, Yun, Zhang, Yinping, Wang, Fang, Jiang, Xin, and Herath, H.M.S.K.

Subjects
*POLYCYCLIC aromatic hydrocarbons, *BIOACCUMULATION, *BACTERIA, *HUMIC acid, *BIODEGRADATION
Abstract

This study evaluated the effect of humic acid (HA) on physicochemical properties of bacterial surfaces and on mass transfer of polycyclic aromatic hydrocarbons (PAHs) from aqueous phase into intracellular bacteria. Due to this process’ potential for bacterial degradation, using Sphingobium sp. PHE3, degradation of phenanthrene (PHE) was compared in HA and non-HA sets. The results showed that approximately 51.1% of PHE at a concentration of 102.0 mg L −1 was biodegraded in the non-HA sets, whereas almost all PHE was biodegraded with HA after 72 h. Interestingly, PHE that accumulated in the intracellular bacteria reached 3.80 mg L −1 for the HA sets, which was significantly higher than that of non-HA. Lipid inclusion bodies appeared when Sphingobium sp. PHE3 was treated with HA. The results were further confirmed by the enhanced bacterial surface sorption capacity for the HA sets. Therefore, we concluded that added HA not only act as carriers and biosurfactants facilitating PHE uptake but also adjust bacteria cell wall properties for internalizing PHE, which ultimately overcame the PHE bioavailability resulting in enhanced biodegradation. [ABSTRACT FROM AUTHOR]

Published
2017
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45. A new highly active La 2 O 3 -CuO-MgO catalyst for the synthesis of cumyl peroxide by catalytic oxidation.

Author

Liu H, Wang K, Cao X, Su J, and Gu Z

Abstract

In this study, different magnesium, copper, lanthanide single metal, and composite multimetal oxide catalysts were prepared via the coprecipitation route for the aerobic oxidation of cumene into cumene hydroperoxide. All catalysts were characterized using several analytical techniques, including XRD, SEM, EDS, FT-IR, BET, CO 2 -TPD, XPS, and TG-DTG. La 2 O 3 -CuO-MgO shows higher oxidation activity and yield than other catalysts. The results of XRD and SEM studies show that the copper and magnesium particles in the catalyst are smaller in size and have a distribution over a larger area due to the introduction of the lanthanum element. The CO 2 -TPD results confirmed that the catalyst has more alkali density and alkali strength, which can excite active sites and prevent the decomposition of cumene hydroperoxide. XPS results show that due to the promotional effect of La 2 O 3 , there are more lattice and active oxygen species in the catalyst, which can effectively utilize the lattice defects under the strong interaction between metal oxides for rapid adsorption and activation, thus improving the oxidation performance. Besides, La 2 O 3 -CuO-MgO exhibits good stability and crystalline structure due to its high oxygen mobility inhibiting coking during the cycle stability test. Finally, the possible reaction pathway and promotional mechanism on La 2 O 3 -CuO-MgO in cumene oxidation are proposed. We expect this study to shed more light on the nature of the surface-active site(s) of La 2 O 3 -CuO-MgO catalyst for cumene oxidation and the development of heterogeneous catalysts with high activity in a wide range of applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Published
2021
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