一种体相加氢脱硫催化剂的程序升温硫化表征

在全自动化学吸附仪上,用程序升温硫化（TPS）技术对一种体相加氢脱硫催化剂进行表征,考察了金属与载体的相互作用、金属间的相互作用以及焙烧温度对这种催化剂硫化性能的影响。结果表明,MoO3负载于Al2O3载体后,硫化峰温大幅降低,并在TPS谱图中体现出分步硫化的过程,证明MoO3与载体间存在相互作用,形成了易于硫化还原的活性中心。当Mo和Ni共同作用于载体时,形成了更易于硫化的Mo-Ni-O复合相。Co的加入加强了Mo与Ni间的协同作用,Co、Mo、Ni与Al形成了更易硫化的活性中心。W的加入反而改变了硫化中心的性质,使硫化温度提高。对（Mo＋Ni）/Al2O3和（Co＋Mo＋Ni）/Al2O3催化剂,于500℃焙烧时,催化剂硫化性能最好。最后得出结论：当Co、Mo、Ni 3种金属共同作用于载体,并于500℃焙烧时,其硫化中心活性最高。     

ICP-AES内标法测定加氢催化剂中的Mo、Co、Ni元素含量

采用硫酸-磷磷混酸为溶剂,采用电感耦合等离子体发射光谱(ICP-AES)内标法对加氢催化剂中的Mo、Co、Ni元素含量进行了测定。考察了硫磷混酸和基体Al2O3、无定形硅铝、Ti O2对Co、Mo、Ni元素测定的影响,结果表明硫磷混酸和基体Al2O3对待测元素的测定有干扰,而基体无定形硅铝和Ti O2对待测元素的测定无干扰。选择用镉(Cd)做内标消除基体干扰,方法回收率在98%~105%,测定相对标准偏差小于0.5%。     

Ni-Mo/Al2O3加氢脱氧催化剂的研究

在连续流动固定床微型反应器内,反应温度240～320℃,氢油比700,液体空速1.5 h-1,压力4.0MPa的条件下,详细考察了Mo-Ni/Al2O3系列催化剂对模型含氧化合物醇和酸的加氢脱氧反应性能.结果表明Mo-Ni/Al2O3催化剂对醇和酸具有高的加氢脱氧活性.其中Mo16Ni6/Al2O3催化剂在280℃时,乙醇、乙酸和丙酸加氢脱氧转化率分别为94.3%、94.9%和98.8%.钼助剂的加入显著地提高Ni基催化剂的加氢脱氧活性,大大地降低了氧化态Ni的还原温度,因为钼助剂的加入抑制了NiO与Al2O3强的相互作用,结果显著地降低了氧化态催化剂中的NiAl2O4相的量,增加了的NiO的量.     

乙二醇对NiMoP/Al2O3上二苯并噻吩加氢脱硫反应的影响

在NiMoP浸渍液中添加不同含量乙二醇,制备了一系列NiMoP/Al2O3催化剂,以二苯并噻吩为模型化合物,考察有机添加剂乙二醇对NiMoP/Al2O3催化剂加氢脱硫性能的影响.结果表明,乙二醇的加入显著提高催化剂的加氢脱硫性能,乙二醇中的羟基与Ni物质的量比为5∶1时,催化剂的加氢脱硫活性最高.乙二醇明显改善NiMoP/Al2O3催化剂的加氢性能.     

Mo、W对Ni /Al2O3催化剂加氢脱氧性能的影响

采用γ-Al2O3栽体，通过浸渍法合成了Mo（W）-Ni／γ-Al2O3系列催化剂。以有机含氧化合物丁酸和丁醇为合成油品的模型化合物，在连续流动固定床反应器中考察了催化剂的加氢脱氧性能。结果表明，Mo（W）-Ni／Al2O3系列催化剂对丁酸和丁醇具有高的加氢脱氧性能；添加Mo（W）可有效地抑制NiO与栽体γ-Al2O3的强相互作用，显著降低催化剂的还原温度，增加催化剂的加氢脱氧活性；添加Mo比添加W的催化剂具有更高的加氢脱氧活性，MoNi6催化剂在280℃条件下，丁酸转化率100％，未完全加氢丁醇的质量分数仅为0．09％。     

脂肪酸甲酯加氢脱氧和加氢脱氮制备生物烷烃

以源于废弃油脂的脂肪酸甲酯(FAMEs)为原料,以Ni Mo/Al2O3为催化剂,采用加氢脱氧和加氢脱氮两步法制备生物烷烃并对反应工艺进行了优化。结果表明,加氢脱氧的最佳反应条件为:反应温度380℃、氢气压力2 MPa、氢气和FAMEs体积比为1000,空速1h–1;加氢脱氮的最佳反应条件为:反应温度310℃、氢气压力2 MPa、氢气和烷烃体积比为2000,空速0.25 h–1。在该优化反应条件下,硫化后的Ni Mo/Al2O3催化FAMEs加氢脱氧能够获得正构烷烃质量分数高于97%的生物烷烃,所得产品采用Ni Mo/Al2O3催化剂进行二次加氢脱氮能够进一步移除超过90%的含氮化合物。硫化后的Ni Mo/Al2O3催化剂在FAMEs加氢脱氧反应中具有良好的结构稳定性和抗积碳性能,使用1000 h后其晶相结构无明显改变且表面积碳量仅为3.18%。     

氢等离子体法制备Ni_2P和Ni_2P/SiO_2加氢脱硫催化剂

采用免焙烧的方法,直接将Ni(NO3)2和(NH4)2HPO4盐的前驱体,或是担载Ni(NO3)2和(NH4)2HPO4盐的前驱体通过氢等离子体法(PR)制备了Ni2P-NC-PR,Ni2P(25)/Si O2-NC-PR加氢脱硫催化剂。以质量分数为0.8%的二苯并噻吩/十氢萘溶液为模型化合物,考察了催化剂的HDS反应性能,并用XRD对催化剂晶相进行了表征。新鲜制备的催化剂在移入固定床反应器之前用体积分数10%H2S/Ar钝化,以保护其结构不被破坏。实验证明,PR还原法制备的Ni2P-NC-PR催化剂的加氢脱硫活性高于Ni2P-C-PR催化剂,PR还原法制备的Ni2P(25)/Si O2-NCPR催化剂的加氢脱硫活性高于Ni2P(25)/Si O2-C-PR催化剂。XRD表征结果表明:Ni2P-NC-PR或Ni2P(25)/Si O2-NC-PR催化剂的颗粒尺寸都小于Ni2P-C-PR或Ni2P(25)/Si O2-C-PR催化剂的颗粒尺寸,催化剂的活性中心较多,其高活性可归于其活性中心数量的增加。     

乙二胺四乙酸对NiMo/Al_2O_3催化剂加氢脱氮性能的影响

以氧化铝为载体,Ni和Mo为金属活性组分,添加不同含量乙二胺四乙酸,采用等体积浸渍法制备系列Ni Mo(x)/Al_2O_3(x为乙二胺四乙酸与Ni物质的量比)重质油加氢处理催化剂,考察乙二胺四乙酸加入量对催化剂加氢脱氮性能的影响,并采用N_2物理吸附-脱附、XRD和HRTEM等对催化剂进行表征。结果表明,乙二胺四乙酸的加入增强了金属组分与氧化铝载体间的相互作用,降低了MoS_2活性相的堆垛层数和片层长度,促进了活性相的分散。乙二胺四乙酸与Ni物质的量比为0.5时,MoS_2活性相堆垛层数和片层长度达到良好的结合,对应的催化剂Ni Mo(0.5)/Al_2O_3具有最优的加氢脱氮性能。     

EDTA对NiW/Al_2O_3催化剂表面金属分散性、形貌及HDN性能的影响

为提高负载催化剂中金属的分散性,以含EDTA螯合剂的浸渍液浸渍制备了NiW/Al2O3加氢处理脱氮催化剂,其中络合剂与Ni的摩尔比为1∶1,考察了EDTA对活性金属分散性及加氢脱氮性能的影响。通过BET、XRD、XPS和HRTEM表征发现,EDTA的引入,可以提高Ni和W在氧化铝载体表面的分散性,W/Al原子比从0.096提高到0.127。EDTA的引入,同时减弱了活性金属与氧化铝载体间的相互作用,有利于形成堆积程度较高的WS2相。EDTA的引入,可以大幅提高催化剂对喹啉的加氢脱氮活性,相对于传统方法制备的催化剂,其加氢脱氮活性可提高27%。     

双环戊二烯连续加氢用镍基催化剂研究

制备了用于双环戊二烯(DCPD)固定床连续式加氢合成桥式四氢双环戊二烯的负载型Ni基催化剂。利用低温氮气吸附(BET)、X射线晶体衍射(XRD)以及程序升温还原(H2–TPR)等手段对催化剂进行表征。结果表明,Ni–Cu/γ–Al2O3催化剂具有更好的加氢活性和稳定性,Cu的加入可降低Ni O的还原温度,促进Ni O在载体表面的分散,有利于加氢活性的提高。此工作为筛选更适合DCPD固定床连续加氢催化剂提供理论和实验依据。     

La掺杂(Na_(0.5)Bi_(0.5))_(0.82)(K_(0.5)Bi_(0.5))_(0.18)TiO_3系统无铅压电陶瓷的制备工艺探讨

采用传统陶瓷工艺,研究了制备[(Na0.5Bi0.5)0.82(K0.5Bi0.5)0.18]1-xLaxTiO3(x=0.00,0.01,0.03,0.05,0.10)无铅压电陶瓷的工艺条件对陶瓷的物相组成、显微结构和压电性能的影响。利用XRD、SEM等技术分析结果表明,合成温度的提高有利于主晶相的形成,且此系统烧成温度范围较窄,故需控制在合适的烧成温度下才能得到高致密度的陶瓷。同时,研究了极化工艺条件对材料压电性能的影响,结果表明,提高极化电场强度、控制适当的极化温度有利于提高材料的压电性能。     

Cd(S_xS_(el-x))颜料的制备

分析了Cd（S_xS_(el-x)）颜料中CdSe所占比例不同时的呈色状况，研究了Cd（S_xS_(el-x)）及ZrSiO_4-Cd（S_xS_(el-x)）颜料的制备方法。     

Quantifying Structural and Solid‐State Viscoelastic Properties of Poly(propylene) (PP)/Poly(oxymethylene) (POM) Blend Films

In this study, isotactic poly(propylene) (PP)/poly(oxymethylene) (POM) blend films, including of POM as minor phase in the range of 10–30 wt%, are prepared in a twin screw extruder equipped with a slit‐die and cast film haul‐off unit. It is found that the blend films show characteristic immiscible matrix‐droplet morphology. Short‐term uniaxial tensile creep behaviors of films imply that the introducing of POM significantly improves the elastic modulus and decreases the total creep strain of PP/POM blends. Creep tests are also performed at various temperatures and long‐term deformations of samples are predicted by applying of time‐temperature superposition principle and the Findley model. It is found that the presence of POM domains into PP matrix enhances the creep resistance of PP especially at high temperatures. It is concluded that the PP‐rich PP/POM blend films show much lower short and long‐term creep strains compared to PP.

     

Compatibility of poly(vinylidene fluoride) (PVDF)/polyamide 12 (PA12) blends

Poly(vinylidene fluoride) (PVDF)/polyamide 12 (PA12) blends showed new peaks in XRD profile with increasing PA12 and the crystallinity of PA12 significantly decreased with the addition of PVDF. PVDF showed three relaxation regions at about −40, 40, and 100°C, respectively, and glass transition temperature (T_g ) of PA12 increased in blends (10.8→30.14°C) and α‐relaxation of PVDF decreased from 100.26 to 86.46°C. Complex viscosities (η*) vs. composition curve showed a great positive deviation in PVDF‐rich and a small negative deviation in PA12‐rich blends. The N—H and C=O stretching band of PA12 shifted slightly toward higher wavelength, and from curve‐fitted data the area of hydrogen‐bonded C=O stretching bands of PA12 decreased with the addition of PVDF, especially in the 30/70 blend, implying the existence of interactions between the β‐hydrogen atom of PVDF and amide carbonyl group of PA12 in the blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1374–1380, 2000     

Separation and concentration processes of solutions of Co(II), Ni(II), Cr(III), Fe(III) and Mn(II) by extraction with toluene-dissolved rosin

The extraction and stripping of Co(II), Ni(II), Cr(III) and Fe(III) from aqueous solutions by rosin dissolved in toluene has been investigated. Results obtained show that rosin is better extractant than abietic or n-lauric acids under comparable conditions. From these results, and the data of Mn(II) solvent extraction studied previously under the same conditions, a separation and concentration process for these five cations in aqueous solutions has been designed. Saturated solutions of Fe(III), Cr(III), Mn(II) and finally Co(II) and Ni(II) have been obtained successively by extraction and stripping, by addition of ammonium hydroxide to obtain the appropriate pH value, and by modifying adequately the organic phase/aqueous phase volume ratio.     

对氯苯乙酮单缩二氨基硫脲Ti(Ⅳ)、Ni(Ⅱ)、Cu(Ⅰ)配合物的直接电化学合成

在以对氯苯乙酮单缩二氨基硫脲 ( HL)为配体的非水溶剂中 ,用 Ti、Ni、Cu金属做阳极 ,用电化学金属阳极氧化法合成了对氯苯乙酮单缩二氨基硫脲与 Ti( )、Ni( )、Cu( )的金属配合物。通过元素分析、红外光谱、紫外光谱、磁化率、摩尔电导等对配体和配合物进行了表征。     

Crystallization behavior and hydrophilicity of poly(vinylidene fluoride)/poly(methyl methacrylate)/poly(vinyl pyrrolidone) ternary blends

Ternary blends composed of matrix polymer poly(vinylidene fluoride) (PVDF) with different proportions of poly(methyl methacrylate) (PMMA)/poly(vinyl pyrrolidone) (PVP) blends were prepared by melt mixing. The miscibility, crystallization behavior, mechanical properties and hydrophilicity of the ternary blends have been investigated. The high compatibility of PVDF/PMMA/PVP ternary blends is induced by strong interactions between the carbonyl groups of the PMMA/PVP blend and the CF₂ or CH₂ group of PVDF. According to the Fourier transform infrared and wide‐angle X‐ray difffraction analyses, the introduction of PMMA does not change the crystalline state (i.e. α phase) of PVDF. By contrast, the addition of PVP in the blends favors the transformation of the crystalline state of PVDF from non‐polar α to polar β phase. Moreover, the crystallinity of the PVDF/PMMA/PVP ternary blends also decreases compared with neat PVDF. Through mechanical analysis, the elongation at break of the blends significantly increases to more than six times that of neat PVDF. This confirms that the addition of the PMMA/PVP blend enhances the toughness of PVDF. Besides, the hydrophilicity of PVDF is remarkably improved by blending with PMMA/PVP; in particular when the content of PVP reaches 30 wt%, the water contact angle displays its lowest value which decreased from 91.4° to 51.0°. Copyright © 2011 Society of Chemical Industry     

导电聚合物PEDOT/PSS-MPEG的制备及性能

引言导电高分子既有导体材料的光电学特性,又有良好的力学性能和可加工性[1],这使得导电高分子材料具有广泛的应用前景。聚噻吩类有机导电材料[2]就是这类材料中的一种。聚噻吩的室温电导率     

Investigation on crystallization behavior and hydrophilicity of poly(vinylidene fluoride)/poly(methyl methacrylate)/poly(vinyl pyrrolidone) ternary blends by solution casting

Ternary blends composed of matrix polymer poly(vinylidene fluoride) (PVDF) with different proportions of poly(methyl methacrylate) (PMMA)/poly(vinyl pyrrolidone) (PVP) blends were prepared by solution casting. The crystallization behavior and hydrophilicity of ternary blends were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), wide angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC), and contact angle test. According to morphological analysis, the surface was full of typical spherulitic structure of PVDF and the average diameter was in the order of 3 μm. The samples presented predominantly β phase of PVDF by solution casting. It indicated that the size of surface spherulites and crystalline phase had little change with the PMMA or PVP addition. Moreover, FTIR demonstrated special interactions among the ternary polymers, which led to the shift of the carbonyl stretching absorption band of PVP. On the other hand, the melting, crystallization temperature, and crystallinity of the blends had a little change compared with the neat PVDF in the first heating process. Except for the content of PVP containing 30 wt %, the crystallinity of PVDF decreased remarkably from 64% to 33% and the value of t_1/2 was not obtained. Besides, the hydrophilicity of PVDF was remarkably improved by blending with PMMA/PVP, especially when the content of PVP reached 30 wt %, the water contact angle displayed the lowest value which decreased from 98.8° to 51.0°. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

(S)-2-(ethyl propionate)-(O-ethyl xanthate)- and (S)-2-(Ethyl isobutyrate)-(O-ethyl xanthate)-mediated RAFT polymerization of vinyl acetate

(S)-2-(Ethyl propionate)-(O-ethyl xanthate) (X1) and (S)-2-(Ethyl isobutyrate)-(O-ethyl xanthate) (X2) were used as the reversible addition-fragmentation chain transfer (RAFT) agents for the radical polymerization of vinyl acetate (VAc). The former showed the better chain transfer ability in the polymerization at 60°C. Kinetic study with both RAFT agents showed pseudo-first order kinetics up to around 85% monomer conversion. Molecular weight of the resulting polymer increased linearly with increase in the monomer conversion up to around 85%. The observed molecular weights calculated from ¹H-NMR spectrum [M_n(NMR)] are close to the corresponding theoretical molecular weights [M_n(theor)]. The corresponding polydispersity index (PDI) of the resulting polymers remained almost constant at around 1.2 up to ∼ 65% monomer conversion and then increased gradually with the further increase in the monomer conversion. Chain-end analysis of the resulting polymers by ¹H-NMR showed clearly that polymerization started with the radical forming out of the xanthate mediator. The negligible homo-chain extension and the hetero-chain extension involving synthesis of poly(VAc)-b-poly(NVP) diblock copolymer were occurred. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012