Advanced Materials Research Vols. 634-638

Abstract: Bulk Ni-Mo-W hydrodesulfurization catalysts with high catalytic activity were synthesized via direct precipitation and controlled pH precipitation method, respectively. Analysis results shows that the preparation method has great influence on the morphology and pore structure, and further influence the hydrodesulfurization activity. The catalyst synthesized by controlled pH precipitation method has much higher surface area and pore volume, 132.9 m2/g and 0.30 mL/g, due to its developed porous structure accumulated by small crystal particles. The activity evaluation indicates that the bulk Ni-Mo-W hydrodesulfurization catalysts has good ultra-deep desulfurization activity of removing complex organic sulfur compounds, such as DBT and Cn-DBT.

Abstract: Metal-organic framework based on Zn2+ and terephthalic acid (TPA) was prepared and characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It was then used as the catalyst for the transesterification between diphenyl carbonate (DPC) and 1, 6-hexandiol (1,6-HD) to polycarbonate diol (PCDL). Compared to Mg-Al layered double hydroxide, triethylenediamine, sodium ethoxide and sodium methoxide, it exhibits the highest catalytic activity for the synthesis of PCDL. Under optimal reaction conditions(n(1,6-HD)/n(DPC) = 1.2, w(catalyst) = 0.03%, 198 °C), the yield of phenol is up to 90.1% in the transesterification process, and PCDL with higher Mn and lower hydroxyl value can be synthesized

Abstract: A Cu-conjugated microporous polymer catalyst (CMP-Cu) was designed and prepared via Sonogashira-Hagihara cross-coupling of 3,8-dibromo-1,10-phenanthroline with 1,3,5-triethyny benzene in toluene. The CMP-Cu showed a catalytic activity for direct carboxylation of terminal alkynes with CO2 in the presence of K2CO3/Cs2CO3 at mild conditions. Several propiolic acids (such as 3-phenylpropiolic acid, 3-(4-nitrophenyl)propiolic acid and 4,4-dimethyl-2-pentynoic acid) have been prepared in a simple and feasible method at room temperature and atmospheric pressure. This catalyst is attractive for CO2 transformation.

Abstract: Substituted phosphotungstic acids containing manganese, chromium, molybdenum and vanadium were prepared, and their catalytic performance on cationic polymerization of β-pinene was also investigated. The experimental results show that the substituted phosphotungstic acids are mono-substituted and keep Keggin structure. The substituted phosphotungstic acids containing Mn or Cr exhibit similar catalytic performance as phosphotungstic acid, instead show bad properties if containing Mo or V. The yield of polymer is up to 44.3 %, and the average number molecular weight is about 1200, and molecular weight distribution index is 1.4.

Abstract: A preparation of novel cobalt-based catalyst on three-dimensionally ordered macroporous (3DOM) silica supporter using poly (methyl methacrylate) monolith as a template has been studied. Monodispersed PMMA colloids were synthesized via an emulsion polymerization, resulting in PMMA spheres with the diameter of 390-400 nm. Two processes were employed for the 3DOM Co/SiO₂ catalyst fabrications, a single-stage sol-gel synthesis (SG) and incipient wetness impregnation method (IM) on synthesized 3DOM SiO₂. Both catalysts were characterized using X-ray Diffraction (XRD), X-ray Absorption Spectroscopy (XAS), Scanning Electron Microscope (SEM) and specific surface area analysis. The XRD and XAS results showed that the doped Co in the 3DOM Co/SiO₂ (SG) were the mix phase of Co(NO₃)₂ and Co₃O₄ , while, only Co₃O₄ was found in the 3DOM Co/SiO₂(IM). The SEM micrographs revealed that both catalysts feature periodic macroporous structure with mean pore diameter of 300-350 nm. Specific surface area of the 3DOM Co/SiO₂ (IM) and the 3DOM Co/SiO₂ (SG) catalysts are 195 m²/g and 286 m²/g, respectively.

Abstract: Bulk vanadium-chromium oxide (VCrO) catalyst was prepared and characterized by N2 adsorption, XRD, NH3-TPD, H2-TPR, and Raman spectroscopy. XRD and Raman results showed that the VCrO catalyst was a kind of VV-CrIII composite oxide mainly consisted of crystalline V2O5 and CrVO4-Ⅲ (orthorhombic). NH3-TPD and H2-TPR results revealed that this catalyst had negligible surface acidity, and was easily reduced due to the formation of CrVO4-Ⅲ. Their catalytic activity was evaluated in the ammoxidation of 3-picoline to nicotinonitrile. Catalytic results showed that the bulk VCrO catalyst was highly active and selective; the nicotinonitrile selectivity and yield was up to 96.1%, 88.2% respectively at atmospheric pressure and 360 °C. The high selectivity was related closely to the low surface acidity of the catalyst.

Abstract: The catalytic synthesis of ethyl acetate from ethanol and acetic acid using Ti2SnC in liquid phase under the atmospheric pressure was studied. The influences of some factors such as catalyst usage, initial reactant molar ratio, reaction temperature and reaction time on acetic acid conversion rate of this reaction system were investigated. The acetic acid conversion rate of 88.12% is achieved while the molar ratio of alcohol and acid is 1:3.6, the amount of catalyst is 0.2000 g, the reaction temperature is 80 °C and the reaction time is 30min. The catalyst Ti2SnC is the ideal catalyst for synthesis of ethyl acetate for good catalytic performance, non-corrosive to equipment, easily separated from product and used repeatedly.

Abstract: Mesoporous MCM-41 molecular sieve was synthesized hydrothermally and selected tetraethoxysilane as silica source. Solid superacid was supported on MCM-41 by dipping and roasting. The samples were characterized by XRD, TEM, and FT-IR. Solid superacid evenly dispersed on MCM-41 with a good pore structure. Their catalytic activities were evaluated in the isomerization of α-pinene. The results show that samples had a good conversion rate and selectivity.

Abstract: A much simpler and more straightforward method, alcohol interchange for the synthesis of titanium glycolate has been suggested. The method implied the reaction of tetraethyl orthosilicate with ethylene glycol on heating in air. The thermal property of titanium glycolate was characterized by thermal gravimetric (TG) and Differencial Thermal Analysis (DTA) analysis. X-ray diffraction (XRD) was used to confirm the conversion of crystalline phase of titanium glycolate from anatase to rutile. The characterization of titanium glycolate and products of its pyrolysis was conducted using scanning electron microscopes.

Abstract: Norbornene dicarboxylate was synthesized through esterification under titanium catalyst. The alcohols are 2-ethyl-1-hexanol, n-octanol, 3,5,5-trimethyl-1-hexanol, and n-decanol. The Structures of compounds were identified by 1H-NMR, and then components were identified by high performance liquid chromatography (HPLC). The yield and purity was over 90 % and 95 %, and color of compounds was colorless or light yellow. The maleate as a by-product was occured by the retro Diels-Alder reaction.