直接合成法制备ZSM-5分子筛及其催化性能的研究

在不添加任何模板剂的情况下,通过控制晶化条件,仅凭Na＋诱导晶体形成,采用水热合成法直接制备出ZSM-5分子筛,并对合成的样品进行X射线衍射、红外光谱照射、扫描电镜扫描,表明该分子筛具有典型的ZSM-5结构。该分子筛经转型后,通过TG检测其酸性,并用于环己烯水合制备环己醇反应,表现出良好的催化性能,反应4 h后,环己醇的收率达到9.4%,并保持较高的对环己醇的选择性（94%左右）。     

Sb-V-SBA-15催化苯酚过氧化氢羟基化的工艺研究

以偏钒酸铵为钒源和三氯化锑为锑源,用后合成法合成了Sb-V-SBA-15[n(Si)/n(V)=25,n(Sb)/n(V)=0.8)]催化剂,采用XRD、N2吸附-脱附法、FT-IR等表征合成的样品。研究了该催化剂催化苯酚过氧化氢羟基化的工艺条件。结果表明,Sb-V-SBA-15仍然保持了SBA-15的高度有序的二维六方孔道结构,且具有较大的比表面积和孔体积,负载的活性组分均匀分布在介孔分子筛表面;以反应时间4 h,反应温度60℃,催化剂用量0.2 g,n(苯酚)∶n(H2O2)∶n(H2O)=1∶1∶2为最佳工艺条件下,苯酚转化率达41.38%,苯二酚选择性为89.27%。     

Engineered Bacterial Flavin-Dependent Monooxygenases for the Regiospecific Hydroxylation of Polycyclic Phenols

4-Hydroxyphenylacetate 3-hydroxylase (4HPA3H), a flavin-dependent monooxygenase from E. coli that catalyzes the hydroxylation of monophenols to catechols, was modified by rational redesign to convert also more bulky substrates, especially phenolic natural products like phenylpropanoids, flavones or coumarins. Selected amino acid positions in the binding pocket of 4HPA3H were exchanged with residues from the homologous protein from Pseudomonas aeruginosa, yielding variants with improved conversion of spacious substrates such as the flavonoid naringenin or the alkaloid mimetic 2-hydroxycarbazole. Reactions were followed by an adapted Fe(III)-catechol chromogenic assay selective for the products. Especially substitution of the residue Y301 facilitated modulation of substrate specificity: introduction of nonaromatic but hydrophobic (iso)leucine resulted in the preference of the substrate ferulic acid (having a guaiacyl (guajacyl) moiety, part of the vanilloid motif) over unsubstituted monophenols. The in vivo (whole-cell biocatalysts) and in vitro (three-enzyme cascade) transformations of substrates by 4HPA3H and its optimized variants was strictly regiospecific and proceeded without generation of byproducts.     

Monodisperse microspheres of copolymers of glycidyl methacrylate and its derivatives as materials for biomedical application

Monodisperse microspheres of copolymers of glycidyl methacrylate were prepared by dispersion polymerization in organic media. The microsphere diameter could be adjusted in the range from 0$md$5 μm to 5μm by changing the monomer concentration, the type of dispersion medium and the content of the comonomers. Terpolymers of glycidyl methacrylate, 2-hydroxyethyl methacrylate and tri(ethylene glycol) dimethacrylate were analysed by thermal decomposition gas chromatography and the compositions of the polymers agreed well with those of the monomer mixtures. The epoxide of the polymer microspheres was hydrolysed to α,β-diol with dilute sulphuric acid without side reactions except the slight formation of sulphate. It was confirmed by the ¹³CFT-NMR spectrum that the main structure of the hydrolysate was that of poly(glyceryl methacrylate). In the reaction of the epoxide with ammonia, the predominant production of tertiary amine was presumed by the relationship between the conversion of the epoxide and the nitrogen content of the reaction product. The amination of the epoxide with secondary amines resulted in the quantitative formation of the corresponding tertiary amines.     

Hydroxylation Reaction of Phenol to Catechol on Lanthanide-Zirconia Catalyst

ＨｙｄｒｏｘｙｌａｔｉｏｎＲｅａｃｔｉｏｎｏｆＰｈｅｎｏｌｔｏＣａｔｅｃｈｏｌｏｎＬａｎｔｈａｎｉｄｅ－ＺｉｒｃｏｎｉａＣａｔａｌｙｓｔＤｅｎｇＧｕｏｃａｉ（邓国才）；ＬｉｕＸｉｎｙｉｎｇ（刘歆颖）；ＸｕＬｉ（徐莉）ＬｉＭｅｎｇｑｉｎｇ（李梦青）；Ｍ...     

苯羟基化制苯酚的工业应用前景

综述了采用N2O,H2O2,O2／H2等氧化剂由苯羟基化制苯酚工艺的研究进展,对上述工艺路线进行了技术经济 评价,并与现行联产丙酮的异丙苯法进行了比较,分析了这些工艺在工业上应用的可能性。根据我国在该领域的研究 现状,提出了苯羟基化合成苯酚工艺的研究方向。     

钛硅沸石TS-2的合成及表征

采用水热法在不同条件下合成出钛硅沸石ＴＳ－２。以ＸＲＤ、ＩＲ、元素分析、ＴＥＭ、ＵＶ－Ｖｉｓ和ＮＨ３－ＴＰＤ表征各样品并研究影响ＴＳ－２合成的因素。发现单聚态硅源有利于钛进入沸石骨架，而诸如Ｎａ＋等杂质电解质离子在结晶前母液中的存在则起相反作用。此结论从各ＴＳ－２样品催化苯酚双氧水羟基化时表现出巨大活性差别中得到进一步证实。ＵＶ－Ｖｉｓ测试发现２１２ｎｍ附近的强烈电子跃迁信号，不仅是四配位骨架钛的表征，也是由钛的高度分散造成的。     

钛硅沸石TS—2催化苯酚羟基化性能研究

以用水热法合成的钛硅沸石ＴＳ－２为催化剂，考察其应用于苯酚羟基化制备苯二酚的性能。结果表明，控制适当的反应速率是提高苯酚转化率Ｈ２Ｏ２利用率的关键，反应速率与温度，原料配比，氧化剂加入方式等因素有关。选择水为溶剂，能在一定程度上抑制副反应的发生，随着催化剂再生次数的增多，苯酚转化率有所提高，产物会分布也有所变化，这可能与沸石骨架中的Ｔｋ环境发生变化有关。     

聚α-蒎烯羟基化和聚α-蒎烯大分子单体的聚合性能

用ＨＣＢｒｏｗｎ硼氢化－氧化反应对聚α－蒎烯环内双键进行羟基化，获得了羟基化结构单元为３３％～５０％的产物。羟基化产物与丙烯酰氯反应，得到了带丙烯酸酯基的聚α－蒎烯大分子单体。大分子单体（平均每条分子链上丙烯酸酯基的数目为２．７）在偶氮二异丁腈引发下进行聚合时，生成交联聚合物，聚合转化率为２０％。在相同条件下与甲基丙烯酸甲酯共聚时，大分子单体的聚合转化率可达６０％。所得聚合物中８７．５％是以甲基丙烯酸甲酯为主链、大分子单体为侧链的接枝共聚物；１２．５％是体型共聚物。     

含氮杂环聚醚砜酮的羟基化改性

用NaBH4作还原剂对含有二氮杂萘酮结构的聚醚砜酮（PPESK）进行羟基化改性。用FT－IR和^1HNMR对还原后的聚醚砜酮（PPESK－OH）的结构进行表征，研究了反应时间、温度、溶剂及反应物浓度的还原反应的影响，并讨论了反应动力学。结果表明，PPESK在DMAc中间NaBH4作还原剂的反应对于羰基的浓度为二级反应，反应活化能为44．2kJ/mol。