SYNTHESIS OF LIGHT OLEFINS FROM SYNGAS VIA DIMETHYLETHR——A NEW TECHNIQUE PROCESS

A new route named as SDTO method for the synthesis of lightolefins from syngas has been proposed.That is to convert syngas todimethylether and then to convert dimethylether to light olefins.The catalystsfor the two conversion reactions have been developed.For the first reaction,the catulySt was synthesized by the combination of methanol synthesis catalystwith γ-Al_2O_3or zeolites which possesses both metallic and acidic functions.Thecatalyst for the second reaction was modified SAPO-34 molecular sieve.Thevariables of the reactions have also been investigated.The results from theserial connection of the two conversion steps without any separation show thatthe yield of C_2~-C_4~- olefins Could be>100g/(m~3 syngas).     

负载型MoOx和VOx催化剂上二甲醚选择氧化制甲醛反应

 考察了负载型MoOx和VOx催化剂上二甲醚选择氧化制甲醛反应的性能. 结果表明,两类催化剂在低温(240~320 ℃)下都具有良好的催化性能,VOx催化剂比MoOx催化剂所需的反应温度低,300 ℃下在VOx/γ-Al2O3催化剂上二甲醚转化率可达20%,甲醛选择性可达70%. 载体对催化剂性能有较大的影响,对于VOx催化剂,使用酸性载体时二甲醚转化率和甲醛选择性更高. 催化剂的稳定性较好, 反应17 h后,VOx/γ-Al2O3催化剂上未检测到有积碳生成.     

Catalytic abatement of CO and volatile organic compounds in waste gases by gold catalysts supported on ceria-modified mesoporous titania and zirconia

Mesoporous oxides TiO2 and ZrO2, synthesized by surfactant templating via a neutral C13(EO)6–Zr(OC3H7)4 assembly pathway, and ceria‐modified TiO2 and ZrO2, prepared by a deposi‐tion–precipitation (DP) method, featuring high surface areas and uniform pore size distributions were used as supports for gold catalysts. The supported gold catalysts were assessed for the cata‐lytic abatement of air pollutants, i.e., CO, CH3OH, and (CH3)2O. The gold was supported on the mes‐oporous oxides by a DP method. The supports and catalysts were characterized by powder X‐ray diffraction, high‐resolution transmission electron microscopy, N2 adsorption–desorption analysis, and temperature‐programmed reduction technique. A high degree of synergistic interaction be‐tween ceria and mesoporous ZrO2 and TiO2 as well as a positive modification of the structural and catalytic properties by ceria was observed. The ceria additive interacts with the mesoporous oxides and induces a strong effect on the reducibility of the supports. The catalytic behavior of the catalysts was discussed to determine the role of the ceria modifying additive and possible interaction be‐tween the gold nanoparticles and ceria‐mesoporous oxide supports. The gold catalysts supported on ceria‐modified mesoporous ZrO2 displayed superior catalytic activity (~100%conversion of CO at 10 °C and CH3OH at 60 °C). The high catalytic activity can be attributed to the ability of the sup‐port to assist oxygen vacancies formation. The studies indicate that the ceria‐modified mesoporous oxide supports have potential as supports for gold‐based catalysts.     

Analysis of the intermolecular interaction between CH(3)OCH(3), CF(3)OCH(3), CF(3)OCF(3), and CH(4): high level ab initio calculations

The intermolecular interaction energies of the CH₃OCH₃? CH₄, CF₃OCH₃? CH₄, and CF₃OCF₃? CH₄ systems were calculated by ab initio molecular orbital method with the electron correlation correction at the second order Møller–Plesset perturbation (MP2) method. The interaction energies of 10 orientations of complexes were calculated for each system. The largest interaction energies calculated for the three systems are ?1.06, ?0.70, and ?0.80 kcal/mol, respectively. The inclusion of electron correlation increases the attraction significantly. It gains the attraction ?1.47, ?1.19, and ?1.27 kcal/mol, respectively. The dispersion interaction is found to be the major source of the attraction in these systems. In the CH₃OCH₃? CH₄ system, the electrostatic interaction (?0.34 kcal/mol) increases the attraction substantially, while the electrostatic energies in the other systems are not large. Fluorine substitution of the ether decreases the electrostatic interaction, and therefore, decreases the attraction. In addition the orientation dependence of the interaction energy is decreased by the substitution. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1472–1479, 2002     

A tetraethylene glycol dimethylether-lithium bis(oxalate)borate (TEGDME-LiBOB) electrolyte for advanced lithium ion batteries

Tetraethylene glycol dimethylether-lithium bis(oxalate)borate (TEGDME-LiBOB) electrolyte is here studied. Electrochemical impedance spectroscopy (EIS) measurements demonstrate that the electrolyte has conductivity higher than 10^− 3 S cm^− 1 at room temperature and about 10^− 2 S cm^− 1 at 60 °C, while thermogravimetry indicates a stability extending up to 180 °C. Sweep voltammetry of the electrolyte shows anodic stability extending over 4.6 V vs. Li and cathodic peak at about 1.5 V vs. Li/Li⁺, caused by a decomposition of LiBOB salt, and following prevented by using a pre-treated Sn-C anode. Furthermore, LiFePO₄ electrode is successfully used as cathode in a lithium cell using the TEGDME-LiBOB electrolyte. The promising electrochemical results, the low cost and the very high safety level candidate the electrolyte here reported as a valid alternative to the conventional electrolyte based on fluorinated salts presently used in the lithium ion battery field.