Ni2P和MoS2催化剂在二苯并噻吩加氢脱硫反应中的氢溢流效应

对分层装填的Ni₂P//MoS₂催化剂上的二苯并噻吩加氢脱硫反应进行了研究。结果表明,分层装填的Ni₂P/Al₂O₃和MoS₂/Al₂O₃催化剂在二苯并噻吩加氢脱硫反应中存在氢溢流效应,氢溢流有助于提高MoS₂催化剂的活性位密度和加氢脱硫反应速率。由于Ni₂P比NiS_x具有更强的氢分子解离能力,Ni₂P//MoS₂催化体系的氢溢流因子略高于NiS_x//MoS₂;相对于NiS_x,Ni₂P对MoS₂催化剂是更好的助剂。     

Deep oxidative desulfurization of benzothiophene and dibenzothiophene with a peroxophosphotungstate–ionic liquid brush assembly

A novel, efficient and reusable heterogeneous catalytic assembly of peroxophosphotungstate held in an ionic liquid brush was synthesized and an extraction and catalytic oxidative desulfurization (ECODS) procedure was developed for a model oil of benzothiophene (BT) and dibenzothiophene (DBT) using 30 wt% hydrogen peroxide as terminal oxidant and methanol as solvent under mild conditions. Several factors that affect sulfur removal were investigated in detail. The highest sulfur removal can reach 100% for BT in 7 h at 70 °C when the molar ratio of H₂O₂, S and catalyst is 10:1:0.025. The sulfur removal for DBT can also reach 100% in 4 h at 50 °C with the same molar ratio of H₂O₂, S and catalyst. The experimental results demonstrate that this ECODS process has no apparent scale‐up effect. The catalyst can be easily recovered (via simple filtration) and recycled five times without a significant decrease in activity. Copyright © 2015 John Wiley & Sons, Ltd.     

End-capped Thiophene Modulated Molecular Packing in 2,8-Dibenzothiophene-based Materials：from Face-to-face to Edge-to-face Stacking

Two new organic crystals of 2,8-bisthienyldibenzothiophene(BTDT) and 2,8-bis-dithienyldibenzothiophene(BDTDT) compounds were successfully obtained.The change of end-capped group from thiophene to dithiophene causes big differences in molecular packing and carrier-transport property.The adjacent molecules of compound BTDT adopt face-to-face π stacking and exhibit two-dimensional interchain interactions.On the contrary,BDTDT molecules are arranged in an edge-to-face motif and show mainly one-dimensional interacting character.The packing mode exerts dramatic effect on the carrier-transport property.The crystal of BTDT belongs to the orthorhombic system,space group P21212 with a = 20.1427(11),b = 4.6016(3),c = 8.6340(5) ,V = 800.27(8) 3,Z = 2,Dc = 1.446 g/cm3,F(000) = 360,S = 1.019,the final R = 0.0491 and wR = 0.0960 for 1605 reflections with I > 2σ(I).The crystal of BDTDT belongs to the orthorhombic system,space group P212121 with a = 7.2636(15),b = 25.359(5),c = 25.359 ?,V = 4670.9(14) ?3,Z = 8,Dc = 1.458 g/cm3,F(000) = 2112,S = 0.880,the final R = 0.0597 and wR = 0.1318 for 8047 reflections with I > 2σ(I).     

多级孔NiMo负载TS-1分子筛催化剂的制备及其加氢脱硫性能

钛硅(TS-1)分子筛的微孔孔道严重限制了其在复杂分子催化转化中的应用,为了克服这一问题,通过酸洗脱、碱刻蚀及二者相结合的方法制备了多级孔 TS-1 分子筛,并采用等体积共浸渍法制备了相应的 NiMo 负载型催化剂;使用 X 射线衍射(XRD)、N₂吸附-脱附、吡啶吸附红外光谱(Py-FTIR)、氢气程序升温还原(H₂-TPR)、X射线光电子能谱(XPS)和高分辨透射电子显微镜(HR-TEM)等方法对多级孔TS-1分子筛的理化性质进行了表征;以二苯并噻吩(DBT)为探针对催化剂的加氢脱硫(HDS)性能进行了评价。结果表明,和常规TS-1分子筛相比,多级孔TS-1分子筛保持了MFI拓扑结构,比表面积增大且具有介孔结构,分子筛表面形成了适量的Brønsted酸中心;相应催化剂上活性金属与载体间相互作用得以改善,MoS₂片晶长度和堆垛层数适宜,形成了更多的 NiMoS活性相;催化剂活性和选择性均有所提升,尤其是酸洗脱获得的 NiMo/AT-TS-1催化剂的活性相较未经处理的NiMo/TS-1催化剂提升了1.2倍,直接脱硫(DDS)路径选择性提升了22%。     

Unique Thia‐Baeyer–Villiger‐Type Oxidation of Dibenzothiophene Sulfoxides Derivatives

The present research has demonstrated that selective C?S bond cleavages of dibenzothiophene and its derivatives are feasible by thia‐Baeyer–Villiger type oxidation, i. e. the oxygen insertion process within a sulfoxide‐carbon linkage, in the presence of porphyrin iron (III) and by ultraviolet irradiation originating from sunlight, high pressure Hg‐lamp or residentially germicidal ultraviolet lamp under very mild conditions. This reaction with tert‐butylhydroperoxide at 30.0 °C leads to dibenzo[1,2]oxathiin‐6‐oxide ( PBS ) in 83.2 % isolated yield or its hydrated products, 2‐(2‐hydroxyphenyl)‐benzenesulfinic derivatives ( HPBS ) in near 100 % yield based HPLC data. PBS and HPBS are a type of biological products detected on the C?S bond cleavage step through various oxidative biodesulfurization ( OBDS ) pathways, and are useful synthetic intermediates and fine chemicals. These observations may contribute on understanding delicately molecular aspect of OBDS in the photosynthesis system, expanding the C‐S cleavage chemistry of S‐heterocyclic compounds and approaching toward biomemic desulfurization with respect to converting sulfur contaminants to chemically beneficial blocks as needed and performing under the ambient conditions.     

镧助剂对Ni2P/SBA-15催化剂结构及加氢脱硫性能的影响

以SBA-15为载体,Ni(NO3)2·6H2O为镍源,(NH4)2HPO4为磷源,制备了初始P/Ni比为0.8的Ni,P/SBA-15前驱体,然后添加La助剂,再经过干燥、焙烧和程序升温氧气还原,制备了一系列不同La含量的La-Ni,P/SBA-15催化剂.采用XRD,N2-吸脱附和XPS对催化剂的结构进行了表征,以...     

NiMo 催化剂上MoS2 形貌与其DBT 加氢脱硫选择性的关系

制备了两个系列不同镍钼负载量的NiMo 催化剂,并用X 衍射、N2 物理吸附和透射电镜进行了表征。以二苯并噻吩
为模型硫化物,在高压固定床微型反应器上对该NiMo 催化剂的加氢脱硫性能进行了评价,研究了MoS2 形貌与催化剂加氢脱
硫选择性之间的关系。结果表明,镍钼负载量对MoS2 形貌有明显的影响。Mo18Ni4 催化剂(含18% MoO3 和4% NiO)上
MoS2 呈多级层状结构,具有较高的加氢脱硫活性和优异的加氢脱硫选择性。加氢选择性与催化剂上活性组分MoS2 的堆积层
数相关联呈很好的线性关系;堆积层数越多,其加氢选择性也越高。     

含镍WP/MCM-41催化剂二苯并噻吩加氢脱硫性能

以MCM-41为载体,以镍（Ni）为助剂,制备了Ni含量不同的WP/MCM-41催化剂。采用XRD、BET、SEM和XPS对催化剂进行了表征;以二苯并噻吩（DBT）为模型化合物,通过高压微反装置考察催化剂的加氢脱硫（HDS）活性。结果表明,Ni的加入促进了活性组分WP的生长并使其晶相尺寸略有增加,一定含量的Ni有利于提高催化剂的比表面积。Ni对WP/MCM-41催化剂二苯并噻吩HDS反应具有促进作用。少量Ni的加入有利于WP活性相的生成并增加了活性位的数量;加入过量的Ni,在催化剂中形成了具有一定活性的类似Ni-W-P结构的物种,减少了活性组分WP所占的比例,从而使催化剂DBT的 HDS活性降低。其中,Ni的质量分数为1%的催化剂（cat-Ni-1）具有相对较高活性,其DBT 脱硫率和转化率分别为76.78%和72.16%,比不加Ni的催化剂分别提高了30.04%和21.62%。二苯并噻吩在WP/MCM-41催化剂上以加氢脱硫途径为主,Ni的加入对提高加氢脱硫途径选择性起到了促进作用,且加氢脱硫选择性随Ni含量的增加而提高。     

SULPHENE INTERMEDIATES IN THE SYNTHESIS OF POLY(P-BENZENE-SULPHONAMIDES) AND POLY(P-BENZENE SULPHONATES)

Abstract

Various sulfides are easily oxidized selectively to the corresponding sulfoxides in quantitative yields by iodosylarene (ArIO) catalyzed by metalloporphyrin (TPPM(III)Cl (M [dbnd] Fe, Mn)). The oxidation system is demonstrated to be a possible model for monooxygenase in the study of the stereochemistry of these sulfoxides. Metalloporphyrin-iodosylarene can initially equilibrate with the oxometalloporphyrin (TPPM(V)=O·Cl) formed in situ. The initial process may involve one-electron transfer from the sulfide to the intermediate oxometalloporphyrin followed by coupling of two resulting charged products, and/or nucleophilic attack of sulfide on oxometalloporphyrin oxygen. The overall reactions are depicted by paths with different electron demands from the results of Hammett plots.     

二苯并噻吩在分散型钼催化剂和原位产生的氢存在下的加氢脱硫Ⅲ. 催化剂前身物、硫化氢、一氧化碳和水对反应的影响(英)

研究了水／ 甲苯乳化液中二苯并噻吩（ 硫芴） 在分散型钼酸、磷钼酸和四硫钼酸铵催化剂存在下的加氢脱硫反应． 反应在高压釜中于３４０ ℃及三种不同的气氛即Ｈ２ ，Ｈ２／Ｈ２ Ｏ和ＣＯ／Ｈ２Ｏ（ＣＯ 和Ｈ２Ｏ 经水煤气转换反应（ ＷＧＳＲ） 产生原位氢） 的存在下进行． 用ＧＣ和ＧＣＭＳ鉴定、分析了气体和液体产物的组成． 结果表明： 对硫芴的加氢脱硫反应，在分散型四硫钼酸铵催化剂存在下，原位产生的氢的效果仅比加入的氢气稍好，而在分散型钼酸和磷钼酸催化剂存在下，原位产生的氢远比加入的氢气有效． 实验结果还表明： 硫化氢能显著提高分散型钼酸和磷钼酸催化剂的加氢脱硫活性，但在分散型四硫钼酸铵催化剂存在下，硫化氢能促进加氢反应而抑制氢解反应． 一氧化碳和水均选择性地抑制氢解反应．