Characterization and catalytic performance of Zr-Mo-oxide catalysts for selective oxidation of methane to formaldehyde

The selective oxidation of methane to formaldehyde has been investigated over a series of Zr-Mo-oxide catalysts. Comparative characterization of these catalysts has been carried out by BET specific surface area (BET), X-ray diffraction (XRD), laser Raman spectroscopy (LRS), temperature programmed reduction of hydrogen (H₂-TPR), and X-ray photoelectron spectroscopy (XPS). The Zr-Mo-oxide catalyst with 12 wt% Mo is found to be highly selective and yields formaldehyde by selective oxidation of methane. The interaction between Mo and Zr induces changes of physicochemical properties such as structure, crystal size, reducible properties, charge of ion and molybdenum oxide species etc., which in turn determines the catalytic performance. These effects are a function of Mo content. Zr(MoO₄)₂in these catalysts might be responsible for selective oxidation of methane to formaldehyde.     

有序介质中二苯甲酰甲烷的酮醇互变异构

用紫外光谱研究了三苯甲酰甲烷在β-环糊精及离子型和非离子型胶束介质中的酮醇互变异构性质,β-环糊精的引入或胶束的形成使酮醇异构平衡向烯醇式方向移动.结果表明,用二苯甲酰甲烷的酮醇互变异构性质能够表征有序介质的微环境性质,确定表面活性物质的临界胶束浓度.     

磁铅石型复合氧化物LaNi_xCo_(1-x)Al_(11)O_(19+δ)催化剂上CH_4和CO_2重整反应的研究

考察了磁铅石型复合氧化物LaNi_(0.5)M_(0.5)Al_(11)O_(19 + δ) (M = Co, Fe, Mn, Cu)和LaNi_xCo_(1-x)Al_(11)O_(19+δ)催化剂在CH_4与CO_2重整制合成 气反应中的催化活性，并应用XRD，TPR，UV-DRS技术着重表征LaNi_xCo_(1-x)Al_ (11)O_(19+δ)催化剂的结构和性能。研究结果表明该系列催化剂具有相同的晶体 结构和相似的还原稳定性。对不同过渡金属取代的催化剂来说，以LaNi_(0.5)Co_ (0.5)Al_(11)O_(19+δ)催化剂具有最好的反应活性。而对于LaNi_xCo_(1-x)Al_ (11)O_(19+δ)系列催化剂，当x ≤ 0.375时，随x值的增大，催化活性明显提高， 但在0.375 ≤ x ≤ 1.0范围内，催化活性几乎保持不变。由此得到结论，对于此 反应来说，控制Ni量在0.375 ≤ x ≤ 0.50范围内比较合适。     

SYNTHESIS AND PROPERTIES OF SULFONATED POLY（ARYLENE ETHER） CONTAINING TRIPHENYL METHANE MOIETIES FROM ISOCYNATE MASKED BISPHENOL

A novel sulfonated poly（arylene ether） containing triphenylmethane moieties was synthesized by the sulfonation of a designed parent polymer using chlorosulfonic acid as sulfonation agent. The sulfonation took place at the para position of the pendant phenyl rings because of the specially designed parent polymer. The position and degree of sulfonation were characterized by ^1H-NMR and elemental analysis. The sulfonated polymers are highly soluble in common organic solvents, such as dimethylsulfoxide, N,N＇-dimethylacetamide, dimethylformamide, ethylene glycol monomethyl ether, and can be readily cast into tough and smooth films from solutions. The films showed good thermal and hydrolysis stabilities. Moreover, Fenton＇s reagent test revealed that the films exhibited superior stability to oxidation. The proton conductivities of the films were comparable with Nation 117 under same conditions. The membrane electrode assembly （MEA） prepared with the asmade film （706 EW, 100 μm dry thickness） shows better cell performance than Nation 115-MEA in the whole current density range.     

等离子体法合成超细碳氮化钛固溶体微粉

本研究以tiCl4、CH4和N3或NH3为原料, 在直流电弧氢等离子体反应器中合成了三元超细碳氮化钛(TiCxN1-x)固溶体微粉。考察了不同氮源及其加入量对产物组成的影响。所得不同固溶度的微粉各自都具有均一的化学组成和相组成, 平均粒径<100um, 比表面>10m^2/g, 主相含量>97±10^-^2┘     

多硝基甲烷Mannich碱稳定性的理论研究

用MNDO SCF-MO方法全优化了系列多硝基甲烷Mannich碱的几何构型, 计算了它们的电子结构。在胺、醛组分相同时, 标题物>N-CH2-Y的特征键CH2-Y的键级随酸组分亲核性的增强而增大。该CH2-Y键级较小是造成Mannich碱在溶液中不稳定的重要原因。C-NO2键的键级在分子中较小, 可能是热或光解等受激分解的引发键, 从电子结构特征上阐明了以硝仿为酸组分的Mannich碱稳定性较差的原因。     

铕(Ⅲ)-二苯甲酰甲烷-聚(苯乙烯-丙烯酸)配合物及其发光性质研究

研究了铕(Ⅲ)和二苯甲酰甲烷(HDBM)形成的有机配合物与聚(苯乙烯-丙烯酸)(PSAA)发生配位反应得到配位聚合物Eu(Ⅲ)-DBM-PSAA。红外光谱、紫外光谱、X光电子能谱的测试表明了Eu^3^+分别与PSAA,DBM^-发生配位,元素分析和电导率测定结果证明了一个Eu^3^+分别与PSAA中三个链节的羧基和一个DBM^-发生配位。从而得到该配合物的结构并对其荧光性进行研究,配位聚合物不能溶于普通有机溶剂,只能溶于丙三醇/异丙醇混合溶剂常温下配合物在紫外光下发出强的红光,主要是Eu离子的^5D0→^7F2的跃迁。     

碳氟等离子体处理PET表面动力学的研究Ⅳ: 静、动态接触角 及变角XPS方法的 应用

利用静、动态接触角及变角XPS来研究碳氟(CF~4/CH~4)气体等离子体处理PET表面的浸水行为,结果表明碳氟等离子体处理的PET浸水后,其表面的憎水性下降。通过PET表面的接触角及F/C比的测定,计算出表面动力学衰减常数k,三种测试方法得到的k值都可以用来表征碳氟等离子体处理PET的表面动力学行为,其中混合气体的k值最小。从而证明混合气体等离子体的改性效果更有利于保持其表面的憎水性。     

甲烷、氮、硫化氢、氨和水混合物的放电反应

以CH4、N2加热含氨、硫化氢水相混合物, 在3500V高压、电火花连续放电24h, 考察H2S在化学进化中的作用. 气相用质谱分析 , 水相经浓缩纯化并制成衍生物, 气相色谱测定有14种氨基酸. 体系中若无硫化氢时, 只生成六种氨基酸. 这表明硫是合成生命基础分子的必需元素, 可能在原始地球空间的化学进化过程中起重要作用.