EMIES/nC_9H_(10)O_2基低共熔溶剂的制备及其氧化脱硫活性的研究

通过简单加热1-乙基-3-甲基咪唑硫酸乙酯(EMIES)离子液体和3-苯丙酸(C_9H_(10)O_2)的混合物,制备了一系列酸性低共熔溶剂EMIES/nC_9H_(10)O_2(n=0.25,0.5,1,2,4)。通过FTIR,~1H NMR和TGA的表征,确定EMIES/nC_9H_(10)O_2的结构。以该低共熔溶剂为催化剂和萃取剂,H_2O_2为氧化剂,组成氧化-萃取脱硫体系,用于脱除模拟油中的硫化物。考察了原料配比、反应温度、氧硫比(O/S)、低共熔溶剂加入量和不同硫化物对脱硫性能的影响。结果表明,在EMIES和C_9H_(10)O_2摩尔比为1∶1,反应温度为50℃,O/S比为8,低共熔溶剂加入量为1.5 g和模拟油5 ml的反应条件下,二苯并噻吩、4,6-二甲基二苯并噻吩和苯并噻吩的脱除率分别为94.8%、91.6%和46.4%。低共熔溶剂可循环使用6次,活性无明显下降。此外,对该氧化-萃取脱硫体系的脱硫机理进行了探讨。     

C6H11NO/nCF3SO3H型低共熔溶剂氧化脱除模拟油中的二苯并噻吩

通过简单加热并搅拌己内酰胺（C₆H₁₁NO）和三氟甲磺酸（CF₃SO₃H）的混合物合成了C₆H₁₁NO/nCF₃SO₃H（n=0.25,0.5,1）型酸性低共熔溶剂。利用红外光谱（FTIR）和氢谱（¹HNMR）确定了C₆H₁₁NO/nCF₃SO₃H的结构特征。以C₆H₁₁NO/0.5CF₃SO₃H低共熔溶剂和H₂O₂组成萃取-氧化脱硫系统,并将其应用于脱除模拟油中的二苯并噻吩（DBT）。研究n(CF₃SO₃H)∶n(C₆H₁₁NO)、反应温度、O/S、C₆H₁₁NO/0.5CF₃SO₃H的加入量和不同类型的硫化物对脱硫效果的影响。实验结果表明,在模拟油体积为5mL、n(CF₃SO₃H)∶n(C₆H₁₁NO)=0.5、反应温度为60℃、 O/S=6、C₆H₁₁NO/0.5CF₃SO₃H的加入量为1.0mL的最佳反应条件下,C₆H₁₁NO/0.5CF₃SO₃H对DBT、4,6-DMDBT、BT和真实油的脱硫率分别达99.4%、98.6%、83.6%和61.6%。红外表征分析了DBT与DESs之间存在相互作用,这种作用促进了氧化脱硫的进程。催化剂5次循环反应以后,其脱硫率仍高达91.9%,表明C₆H₁₁NO/0.5CF₃SO₃H低共熔溶剂具有较高的脱硫性能和稳定性。     

苯酚型低共熔溶剂中硫酸钛作为催化剂高效氧化脱硫

低共熔溶剂广泛应用于氧化脱硫过程,开发新型的低共熔溶剂并进一步提升脱硫效果具有重要的意义。 以氯化胆碱为氢键受体,苯酚为氢键供体合成了ChCl/2Ph型低共熔溶剂。通过FT-IR和¹H NMR证实了苯酚和氯化胆碱之间存在氢键作用。以苯酚型低共熔溶剂为萃取剂,双氧水为氧化剂,硫酸钛为催化剂氧化脱除模拟油中的二苯并噻吩。考察了反应温度、V(ChCl/2Ph)/V(Oil)、n(H₂O₂)/n(S)、催化剂用量以及硫化物类型对脱硫率影响。实验表明最佳反应条件如下：模拟油量为5 ml,V(ChCl/2Ph)/V(Oil)=2∶10, n(H₂O₂)/n(S)=6,催化剂用量为0.01 g,反应温度为40℃,反应时间180 min。在此条件下脱硫率可以达到98.2%。求得体系的表观活化能为41.9 kJ/mol。含有催化剂的低共熔溶剂相可以重复使用5次且活性没有明显降低。机理研究表明形成钛的过氧化物和Br?nsted酸性是具有较高脱硫活性的关键。     

ZrO2/SiO2催化剂的制备及其氧化脱硫性能研究

以己内酰胺-八水氧氯化锆低共熔溶剂为添加组分,采用溶胶-凝胶法合成含锆的硅胶,再经过高温煅烧得到n-ZrO₂/SiO₂ （n=2%,4%,6%） 负载型催化剂。并用红外光谱（FT-IR）、X射线衍射（XRD）、扫描电镜（SEM）、N₂吸附-脱附、X射线光电子能谱（XPS）对其进行结构表征,确定ZrO₂成功负载到SiO₂上。以ZrO₂/SiO₂为催化剂和吸附剂,H₂O₂为氧化剂组成催化氧化脱硫体系,并应用于模拟油脱硫。分别考察了氧化锆负载量、反应温度、氧硫比、催化剂加入量及不同类型的硫化物对脱硫效果的影响。实验结果表明,在反应温度为70℃、n（H₂O₂）/n（S）=4（摩尔比）、4%-ZrO₂/SiO₂的加入量为0.2 g的最佳反应条件下,氧化脱硫体系对二苯并噻吩（DBT）、4,6-二甲基二苯并噻吩（4,6-DMDBT）和苯并噻吩（BT）的脱除率分别为98.7%、93%和65.9%。且4%-ZrO₂/SiO₂回收利用5次后,DBT脱除率仍可达到91.8%。     

酸性低共熔溶剂四乙基氯化铵/三氟乙酸高效催化氧化脱除模拟油中的硫化物

将适量四乙基氯化铵（TEAC）和三氟乙酸（TFA）通过简单搅拌加热（70℃）的方式合成一系列新型低共熔溶剂TEAC/nTFA（n=0.5,1,1.5,2）,并对其结构进行红外光谱和核磁共振氢谱表征分析。以TEAC/nTFA为催化剂和萃取剂,H₂O₂为氧化剂研究其对模拟油中硫化物的脱除效果。并考察了n_（TEAC（/n_（TFA（、温度、O/S、不同硫化物等反应条件对脱硫效率的影响。在最佳反应条件下,TEAC/TFA对二苯并噻吩（DBT（,苯并噻吩（BT（和噻吩（TH（的脱除率分别达到95.4%,56.2%和23.4%。基于一级动力学和Arrhenius方程,估算出氧化脱除DBT所需的活化能约为56.8 kJ·mol^-1。反应活化能较低,氧化反应较易进行。TEAC/TFA回收利用5次之后活性无明显降低。     

甲基咪唑盐酸盐/草酸型低共熔溶剂的制备及其在模拟油中氧化脱硫中的应用

通过简单加热并搅拌甲基咪唑盐酸盐和草酸的混合物合成了甲基咪唑盐酸盐/草酸（[HMIM]Cl/H₂C₂O₄）型酸性低共熔溶剂,以[HMIM]Cl/H₂C₂O₄为萃取剂和催化剂、H₂O₂为氧化剂催化氧化法脱除模拟油中的二苯并噻吩,考察不同的脱硫体系、反应温度、催化剂加入量、氧硫比、模拟油中含硫化合物类型对脱硫率的影响。实验表明,在反应温度为40℃、模拟油量为5 ml、[HMIM]Cl/H₂C₂O₄加入量为1.25 ml、O/S 12、反应时间为140 min的最佳反应条件下二苯并噻吩的脱除率可以达到92.2%。动力学分析表明,该氧化脱硫体系符合一级反应动力学方程。循环使用7次后催化剂的活性没有明显降低。     

磷钨酸/SBA-15催化氧化-萃取柴油脱硫

以自制的SBA-15为载体,磷钨酸为活性组分,用过量浸渍法制备了HPW/SBA-15催化剂,并采用SEM、BET和TG-DTA对催化剂进行表征分析。H₂O₂为氧化剂,十六烷基三甲基溴化铵（CTAB）为相转移剂,以二苯并噻吩（DBT）的模型化合物（DBT为溶质、正辛烷为溶剂）进行氧化脱除为探针反应,考察了磷钨酸负载量和HPW/SBA-15的焙烧温度对催化剂活性的影响,同时考察了氧化-萃取工艺条件对真实柴油脱硫效果的影响。实验结果表明,磷钨酸最佳负载量为30%,HPW/SBA-15在250℃焙烧处理时活性最高;在n(H₂O₂)：n(S)=6、HPW/SBA-15用量为2.5%（基于柴油质量）、CTAB用量为0.4%（基于柴油质量）、萃取级数为4、温度60℃反应1.5h的条件下,柴油硫含量从1317mg/L降到39mg/L,脱硫率达到97.0%、收率不低于85.0%。气相色谱结果显示,该催化氧化脱硫体系容易脱除柴油中加氢难以脱除的二苯并噻吩及其衍生物。     

焦炉煤气常量含碳气氛对加氢脱硫催化剂活性、选择性和积炭的影响

利用微型固定床反应装置对工业Fe-Mo预加氢脱硫催化剂进行加氢脱硫(HDS)评价，研究焦炉煤气中不同常量含碳原料组分(CH₄、C₂H₄、C₂H₆、CO、CO₂)对催化剂加氢活性、选择性以及积炭的影响，并采用红外碳硫分析仪、N₂吸附-脱附、Raman以及TPRS-MS对催化剂进行表征。结果表明：在N₂气氛下，COS、CS₂和C₄H₄S加氢转化由易到难顺序为：COS>CS₂>C₄H₄S，但COS加氢转化受含碳气氛影响最明显，致使焦炉煤气加氢脱硫中COS难以完全脱除；不同气氛对硫化物加氢选择性都会产生影响，其中C₂H₄气氛对选择性影响最明显，而对H₂S收率影响最明显的是CO₂和CO；不同含碳...     

离子液体中过氧钼酸盐催化燃油深度氧化脱硫

以过氧化氢为氧化剂,[Omim]PF₆离子液体为萃取剂,[C₁₆mim]₂ Mo₂O₁₁为催化剂建立了萃取催化氧化脱硫体系（ECODS）。该反应体系在非常温和的条件下可使DBT的脱除率最高达到99.4%,大大优于单纯的萃取脱硫和萃取氧化脱硫体系。不同硫化物在该体系下的脱硫效果为：DBT >BT >TH。催化体系循环使用10次后催化反应活性未见明显下降。将此催化体系直接用于市售的汽油和柴油,可使其中硫含量降低至12.70mg/L和11.62mg/L。     

耐高温聚酰亚胺类胶粘剂制备及性能分析

为了分析影响耐高温聚酰亚胺类胶粘剂性能的因素,使用C₁₂H₁₂N₂O和C₂₇H₂₆N₂O₂作为二胺单体,C₁₇H₆O₇作为二酐单体,通过封端剂C₄H₂O₃和反应溶剂C₅H₉NO的共同作用制备了一种聚酰亚胺胶粘剂,测试了不同因素对胶粘剂粘接性能的影响。结果表明,固体质量分数、粘结件表面粗糙度、C₁₂H₁₂N₂O和C₂₇H₂₆N₂O₂单体的摩尔比、二酐与二胺单体的摩尔比、聚酰胺酸固化工艺、亚胺化程度和亚胺化方式都会对耐高温聚酰亚胺类胶粘剂的性能产生影响。当胶粘剂固体质量分数为30%、表面粗糙度的打磨砂纸型号为600...     

Catalytic reduction of SO2 over supported transition-metal oxide catalysts with C2H4 as a reducing agent

This work investigates performances of supported transition-metal oxide catalysts for the catalytic reduction of SO₂ with C₂H₄ as a reducing agent. Experimental results indicate that the active species, the support, the feed ratio of C₂H₄/SO₂, and pretreatment are all important factors affecting catalyst activity. Fe₂O₃/γ-Al₂O₃ was found to be the most active catalyst among six γ-Al₂O₃-supported metal oxide catalysts tested. With Fe₂O₃ as the active species, of the supports tested, CeO₂ is the most suitable one. Using this Fe₂O₃/CeO₂ catalyst, we found that the optimal Fe content is 10 wt.%, the optimal feed ratio of C₂H₄/SO₂ is 1:1, and the catalyst presulfidized by H₂+H₂S exhibits a higher performance than those pretreated with H₂ or He. Although the feed concentrations of C₂H₄:SO₂ being 3000:3000 ppm provide a higher conversion of SO₂, the sulfur yield decreases drastically at temperatures above 300 °C. With higher feed concentrations, maximum yield appears at higher temperatures. The C₂H₄ temperature-programmed desorption (C₂H₄-TPD) and SO₂-TPD desorption patterns illustrate that Fe₂O₃/CeO₂ can adsorb and desorb C₂H₄ and SO₂ more easily than can Fe₂O₃/γ-Al₂O₃. Moreover, the SO₂-TPD patterns further show that Fe₂O₃/γ-Al₂O₃ is more seriously inhibited by SO₂. These findings may properly explain why Fe₂O₃/CeO₂ has a higher activity for the reduction of SO₂.     

L-苏氨酸衍生物的合成及性质

以L-苏氨酸和香兰素为起始原料,设计并合成了9种新型光催化材料C₂₄H₂₈K₂N₂O₁₀Sn、C₂₄H₂₈FeK₂N₂O₁₀、C₂₄H₃₆FeK₂N₄O₁₀、C₂₄H₂₈Cl₂K₂N₂NiO₁₀、C₂₄H₂₈K₂N₄NiO₁₆、C₂₄H₂₈K₂N₂O₁₀Zn、C28H34K2N2NiO14、C₂₄H₂₈CoK₂N₂O₁₀和C₂₄H₂₈BaK₂N₂O₁₀,通过IR、MS(EI)、荧光分析和元素分析等对形成的希夫碱及其金属衍生物进行表征,推断其可能的化学结构,用紫外漫吸收研究光催化性质, 预测是一类潜在的环保性光催化材料。     

Surface properties and reactivity of Cu/γ-Al2O3 catalysts for NO reduction by C3H6: Influences of calcination temperatures and additives

The influences of calcination temperatures and additives for 10 wt.% Cu/γ-Al₂O₃ catalysts on the surface properties and reactivity for NO reduction by C₃H₆ in the presence of excess oxygen were investigated. The results of XRD and XPS show that the 10 wt.% Cu/γ-Al₂O₃ catalysts calcined below 973 K possess highly dispersed surface and bulk CuO phases. The 10 wt.% Cu/γ-Al₂O₃ and 10 wt.% Mn–10 wt.% Cu/γ-Al₂O₃ catalysts calcined at 1073 K possess a CuAl₂O₄ phase with a spinel-type structure. In addition, the 10 wt.% La–10 wt.% Cu/γ-Al₂O₃ catalyst calcined at 1073 K possesses a bulk CuO phase. The result of NO reduction by C₃H₆ shows that the CuAl₂O₄ is a more active phase than the highly dispersed and bulk CuO phase. However, the 10 wt.% Mn–10 wt.% Cu/γ-Al₂O₃ catalyst calcined at 1073 K possesses significantly lower reactivity for NO reduction than the 10 wt.% Cu/γ-Al₂O₃ catalyst calcined at 1073 K, although these catalysts possess the same CuAl₂O₄ phase. The low reactivity for NO reduction for 10 wt.% Mn–10 wt.% Cu/γ-Al₂O₃ catalyst calcined at 1073 K is attributed to the formation of less active CuAl₂O₄ phase with high aggregation and preferential promotion of C₃H₆ combustion to CO_x by MnO₂. The engine dynamometer test for NO reduction shows that the C₃H₆ is a more effective reducing agent for NO reduction than the C₂H₅OH. The maximum reactivity for NO reduction by C₃H₆ is reached when the NO/C₃H₆ ratio is one.     

Synthesis, characterization and catalytic properties of SAPO-34 synthesized using diethylamine as a template

SAPO-34 molecular sieve was successfully synthesized using diethylamine (DEA) as a template. The influence of template concentration and silica concentration on the synthesis were investigated. Pure SAPO-34 could be obtained when n(DEA)/n(Al₂O₃)  1.5 and n(SiO₂)/n(Al₂O₃) > 0.1 in the synthesis gel. Further increase of DEA concentration in the starting gel [n(DEA)/n(Al₂O₃) > 3] has a negative effect on both crystallinity and crystal yield. The products were characterized by XRD, XRF, SEM, NMR, FT-IR, TG-DTA and nitrogen adsorption techniques. It was found that SAPO-34 synthesized with DEA as a template has the characteristic of high silicon incorporation and exhibits good thermal and hydrothermal stability. The catalytic performance of SAPO-34 was tested by methanol-to-olefin (MTO) reaction and high olefins (C₂H₄ + C₃H₆) selectivity was obtained.     

Surface and structure characteristics of commercial K-Feldspar powders: Effects of temperature and leaching media

This study presents morphological and structural variations of K-Feldspar mineral after acid treatment. Both organic and inorganic acids such as C₂H₂O₄, HCl, HNO₃ and H₂SO₄ were employed for this purpose. Another aim of this study was to find an optimum experimental condition for iron (Fe) removal with a minimum damage on the structure of K-Feldspar in which high whiteness index is obtained. The effect of different parameters such as concentration, pH and temperature on the final structure of this mineral was investigated. To find out the chemical composition of powder, XRF was utilized. FTIR, XRD and SEM were employed to study the structure of mineral. Spectrophotometry was chosen to analyze whiteness index of powder after acid treatment. It was found that O—Al—O bond at 647 cm^-1 for H₂SO₄ and HNO₃ treated sample disappeared. However, HCl and C₂H₂O₄ were ineffective at this band. In addition, the results revealed an increase in K-Feldspar content, a decrease in Fe content, an increase in whiteness index and no significant structural change for C₂H₂O₄ leached sample. Whiteness index of 91% was obtained for C₂H₂O₄ leached sample with the pH of 2.5 to 3 at temperature of 50℃ and during 1 h.     

Stable titanium metal-organic framework with strong binding affinity for ethane removal

Direct separation of high purity ethylene (C₂H₄) from an ethane (C₂H₆)/ethylene mixture is a critical and challenging task owing to the very similar molecular size and physical properties of the two components. While some studies have attempted this separation, there is a lack of excellent porous materials with strong binding affinity for C₂H₆-selective adsorption via an energy-efficient adsorptive separation process. Herein, we report a titanium metal-organic framework with strong binding affinity and excellent stability for the highly efficient removal of C₂H₆ from C₂H₆/C₂H₄ mixtures. Single component adsorption isotherms demonstrated a larger amount of adsorbed ethane (1.16 mmol·g^-1 under 1 kPa) and high C₂H₆/C₂H₄ selectivity (2.7) for equimolar C₂H₆/C₂H₄ mixtures, especially in the low-pressure range, which is further confirmed by the results of grand canonical Monte Carlo simulations for C₂H₆ adsorption in this framework. The experimental breakthrough curves showed that C₂H₄ with a high purity was collected directly from both 1:9 and 1:15 C₂H₆/C₂H₄ (volume ratio) mixtures at 298 K and 100 kPa. Moreover, the unchanged adsorption and separation performance after cycling experiments confirmed the promising applicability of this material in future.     

Efficient separation of C4 olefins using tantalum pentafluor oxide anion-pillared hybrid microporous material

With the increasing demand for synthetic rubber, the purification of 1,3-butadiene (C₄H₆) is of great industrial significance. Herein, the successful removal of n-butene (n-C₄H₈) and iso-butene (iso-C₄H₈) from 1,3-butadiene (C₄H₆) was realized by synthesizing a novel TaOF₅^2- anion-pillared ultramicroporous material TaOFFIVE-3-Ni (also referred to as ZU-96, TaOFFIVE=TaOF₅^2-, 3=pyrazine). Single-component adsorption isotherms show that TaOFFIVE-3-Ni can achieve the exclusion of n-C₄H₈ and iso-C₄H₈ in the low pressure region (0-30 kPa), and uptake C₄H₆ with a high capacity of 92.78 cm³·cm^-3 (298 K and 100 kPa). The uptake ratio of C₄H₆/iso-C₄H₈ on TaOFFIVE-3-Ni was 20.83 (298 K and 100 kPa), which was the highest among the state-of-the-art adsorbents reported so far. With the rotation of anion and pyrazine ring, the pore size changes continuously, which makes smaller-size C₄H₆ enter the channel while larger-size n-C₄H₈ and iso-C₄H₈ are completely blocked. The excellent breakthrough performance of TaOFFIVE-3-Ni shows great potential in industrial separation of C₄ olefins. The specific adsorption binding sites within ZU-96 was further revealed through the modeling calculation.     

Preparation of CexZr1−xO2 (x = 0.75, 0.62) solid solution and its application in Pd-only three-way catalysts

Nanoparticles of Ce_xZr_1−xO₂ (x = 0.75, 0.62) were prepared by the oxidation-coprecipitation method using H₂O₂ as an oxidant, and characterized by N₂ adsorption, XRD and H₂-TPR. Ce_xZr_1−xO₂ prepared had single fluorite cubic structure, good thermal stability and reduction property. With the increasing of Ce/Zr ratio, the surface area of Ce_xZr_1−xO₂ increased, but thermal stability of Ce_xZr_1−xO₂ decreased. The surface area of Ce_0.62Zr_0.38O₂ was 41.2 m²/g after calcination in air at 900 °C for 6 h. TPR results showed the formation of solid solution promoted the reduction of CeO₂, and the reduction properties of Ce_xZr_1−xO₂ were enhanced by the cycle of TPR-reoxidation. The Pd-only three-way catalysts (TWC) were prepared by the impregnation method, in which Ce_0.75Zr_0.25O₂ was used as the active washcoat and Pd loading was 0.7 g/L. In the test of Air/Fuel, the conversion of C₃H₈ was close to 100% and NO was completely converted at λ < 1.025. The high conversion of C₃H₈ was induced by the steam reform and dissociation adsorption reaction of C₃H₈. Pd-only catalyst using Ce_0.75Zr_0.25O₂ as active washcoat showed high light off activity, the reaction temperatures (T₅₀) of 50% conversion of CO, C₃H₈ and NO were 180, 200 and 205 °C, respectively. However, the conversions of C₃H₈ and NO showed oscillation with continuously increasing the reaction temperature. The presence of La₂O₃ in washcoat decreased the light off activity and suppressed the oscillation of C₃H₈ and NO conversion. After being aged at 900 °C for 4 h, the operation windows of catalysts shifted slightly to rich burn. The presence of La₂O₃ in active washcoat can enhance the thermal stability of catalyst significantly.