Enhanced hydrodeoxygenation of lignin-derived anisole to arenes catalyzed by Mn-doped Cu/Al_(2)O_(3)

Lignin is a renewable carbon resource to produce arenes due to its abundant aromatic structures.For the liquid-phase hydrodeoxygenation(HDO)based on metallic catalysts,the preservation of aromatic rings in lignin or its derivatives remains a challenge.Herein,we synthesized Mndoped Cu/Al_(2)O_(3) catalysts from layered double hydroxides(LDHs)for liquid-phase HDO of lignin-derived anisole.Mn doping significantly enhanced the selective deoxygenation of anisole to arenes and inhibited the saturated hydrogenation on Cu/Al_(2)O_(3).With Mn doping increasing,the surface of Cu particles was modified with MnO_(x) along with enhanced generation of oxygen vacancies(Ov).The evolution of active sites structure led to a controllable adsorption geometry of anisole,which was beneficial for increasing arenes selectivity.As a result,the arenes selectivity obtained on 4Cu/8Mn4AlO_(x) was increased to be more than 6 folds of that value on 4Cu/4Al_(2)O_(3) over the synergistic sites between metal Cu and Ov generated on MnO_(x).

Intrinsic kinetics of catalytic hydrogenation of 2-nitro-4-acetylamino anisole to 2-amino-4-acetylamino anisole over Raney nickel catalyst

The catalytic hydrogenation of 2-nitro-4-acetylamino anisole(NMA)is a less-polluting and efficient method to produce 2-amino-4-acetamino anisole(AMA).However,the kinetics of catalytic hydrogenation of NMA to AMA remains obscure.In this work,the kinetic models including power-law model and Langmuir-Hinshelwood-Hougen-Watson(LHHW)model of NMA hydrogenation to AMA catalyzed by Raney nickel catalyst were investigated.All experiments were carried out under the elimination of mass transfer resistance within the temperature range of 70–100°C and the hydrogen pressure of 0.8–1.5 MPa.The reaction was found to follow 0.52-order kinetics with respect to the NMA concentration and 1.10-order kinetics in terms of hydrogen pressure.Based on the LHHW model,the dual-site dissociation adsorption of hydrogen was analyzed to be the rate determining step.The research of intrinsic kinetics of NMA to AMA provides the guidance for the reactor design and inspires the catalyst modification.

Catalytic Acylation of Anisole over Some Zeolites

Methoxyacetophenone(4 MAP) was synthesized by the acylation of anisole with acetic anhydride in the presence of HY zeolite. The addition of an appropriate amount of some solvent such as dichloromethane, chloroform, carbon disulfide or chlorobenzene to the reaction system can improve the yield of the acylated product to a certain extent. HY zeolite used can be recovered, and reused after being regenerated, obtaining almost the same yield of 4 MAP as the fresh zeolite.

ZEOLITE－CATALYZED FRIEDEL－CRAFTS ACYLATION OF AROMATICS：I》．SYNTHESIS OF 4－ACYL ANISOLE WITH A HY CATALYST

A series of aromatic ketones 4-acyl anisole were synthesized with high yield by using carboxylic acids as acylating agents and a HY zeolite as catalyst.

GROWTH OF o-DICYANOVINYL ANISOLE(DIVA) CRYSTAL IN ORGANIC SOLVENTS

Crystal growth habits of O-Dicyanovinyl anisole (DIVA) in organic solvents are described

An efficient bifunctional Ni-Nb_(2)O_(5)nanocatalysts for the hydrodeoxygenation of anisole

The Ni-Nb_(2)O_(5)nanocatalysts have been prepared by the solgel method,and the catalytic hydrodeoxygenation(HDO)performance of anisole as model compound is studied.The results show that Nb exists as amorphous Nb_(2)O_(5)species,which can promote Ni dispersion.The addition of Nb_(2)O_(5)increases the acidity of the catalyst.However,when the content of niobium is high,there is an inactive Nb-Ni-O mixed phase.The size and morphology of Ni grains in catalysts are different due to the difference of Nb/Ni molar ratio.The Ni_(0.9)Nb_(0.1)sample has the largest surface area of 170.8 m^(2)·g^(-1)among the catalysts prepared in different Nb/Ni molar ratios,which is mainly composed of spherical nanoparticles and crack pores.The HDO of anisole follows the reaction route of the hydrogenation HYD route.The Ni_(0.9)Nb_(0.1)catalyst displayed a higher HDO performance for anisole than Ni catalyst.The selectivity to cyclohexane over the Ni_(0.9)Nb_(0.1)sample is about 10 times that of Ni catalyst at 220℃and 3 MPa H_(2).The selectivity of cyclohexane is increased with the increase of reaction temperature.The anisole is almost completely transformed into cyclohexane at 240℃,3 MPa H_(2)and 4 h.

顶空固相微萃取-气相色谱质谱法测定水体中的苯甲醚

建立了顶空固相微萃取-气相色谱质谱法定性定量检测水中苯甲醚的分析方法。对影响检测结果的因素如萃取头的选择、萃取时间等进行了优化。经过条件优化,方法在1~1000μg/L范围内线性良好,线性相关系数>0.999,实际水样加标质量浓度分别为10,60,300μg/L时,加标回收率为85%~120%,相对标准偏差(RSD)为3.95%~6.72%。全扫描模式下,苯甲醚的检出限为0.3μg/L。实验结果表明,该方法快速、简便、灵敏度高,方法精密度和准确度均能满足水中微量及痕量苯甲醚检测的要求。

DETECTION OF INTERMEDIATES IN REACTION BETWEEN N , N'-DI (P-METHYL) PHENYL MONOTHIOXAMIDES AND 1, 3-DIAMINE TRIMETHYLENE USING RAMAN SPECTROSCOPY

Reman spectroscopy is used as a tool to monitor the reaction between N,N'-di(pmethyl)monothioxamides and 1,3-diamine trimethylene and to detect the reaction intermediate. By observing changes of 1024 cm^(-1) C=S band and appearance of a new bend at around 1720 cm^(-1), the reaction mechanism is discussed.

Ni/SiO_(2)催化剂催化2-硝基-4-乙酰胺基苯甲醚加氢性能研究

Ni系催化剂具有原料丰富,价格低的优点,本研究将Ni负载在SiO_(2)表面,用于2-硝基-4-乙酰胺基苯甲醚(NMA)加氢反应。Ni/SiO_(2)催化剂采用溶胶-凝胶法制备,用BET、XRD、SEM、TEM、NH_(3)-TPD、H_(2)-TPR等表征技术对催化剂结构进行表征,考察了加氢反应性能随催化剂结构、反应温度和压力变化规律。以商用雷尼镍催化剂作为对照,考察催化剂催化NMA加氢反应性能。研究结果表明:Ni负载量为30%时,Ni/SiO_(2)催化剂适量的酸性和Ni纳米粒子之间的协同作用使得Ni/SiO_(2)表现出最高的催化活性;在100℃、加氢压力1.8 MPa条件下反应2 h, NMA转化率达到100%,目标产物2-氨基-4-乙酰氨基苯甲醚(AMA)选择性超过99.3%。

NiCu-based catalysts for the low-temperature hydrodeoxygenation of anisole:Effect of the metal ratio on SiO_(2)andγ-Al_(2)O_(3)supports

The effects of the metal ratio of NiCu catalysts on the low-temperature hydrodeoxygenation(HDO)of anisole were assessed on a neutral SiO_(2) and an acidicγ-Al_(2)O_(3) support.The activity of SiO_(2)-supported catalysts increases with the Ni content in the NiCu phase,related to Ni’s hydrogenation capacity.In contrast,on aγ-Al_(2)O_(3) support,the activity decreases with the Ni content.Overall,Al_(2)O_(3)-supported catalysts,exhibiting a smaller NiCu alloy particle size,are more active than SiO_(2)-supported ones.In terms of selectivity,SiO_(2)-supported catalysts mainly hydrogenate anisole to methoxycyclohexane,while,particularly at higher conversions,γ-Al_(2)O_(3)-supported catalysts are able to further convert methoxycyclohexane to cyclohexane,demonstrating the importance of acid sites for low-temperature HDO.The Ni/Cu ratio also steers the selectivity,but not the catalyst stability.Deactivation phenomena are only support dependent:while on SiO_(2)-supported catalysts,active site sintering occurs,attributed to weak stabilization of metal particles by the support,acid catalyzed coking is the main cause of deactivation on theγ-Al_(2)O_(3)-supported catalysts.

高效液相色谱法测定邻氨基苯甲醚产品或反应液中7种组分的质量分数

建立了高效液相色谱法同时测定邻氨基苯甲醚合成工艺中邻氨基苯酚、对氨基苯甲醚、苯胺、对氨基苯酚、邻氨基苯甲醚、邻氨基苯乙醚和邻氯苯胺质量分数的方法。优化的色谱条件为:以Inert Sustain C18色谱柱(250 mm×4.6 mm,5μm)为分析柱,以磷酸二氢钾和甲醇为流动相,采用梯度洗脱方式分离待测物和其他杂质组分,在290 nm波长下以外标法定量。结果表明:各待测物与相邻组分的分离度大于1.5;主成分邻氨基苯甲醚和其他6种杂质组分分别在质量浓度为90.0~900.0 mg·L^(-1)、0.45~4.5 mg·L^(-1)内呈线性关系,加标回收率分别为99.0%~101.0%、98.0%~102.5%,测定值的相对标准偏差(n=3)为0.13%~5.0%.

不同主产区小茴香药材质量评价

研究旨在全面了解全国各产地小茴香药材质量情况。在小茴香的7个主要产地设置采集21批药材样本,按照《中华人民共和国药典》方法测定其挥发油、反式茴香脑、5种重金属的含量和9种有机氯类农药残留量并进行分析评价。研究表明,小茴香药材质量状况良好,各产地小茴香的挥发油和反式茴香脑指标均高于药典要求,5种重金属含量低,9种有机氯类农药残留量未检出,符合中药材安全的要求。甘肃省玉门市产挥发油和反式茴香脑含量最高,甘肃省民勤县、海原县、景泰县,山西省朔州,内蒙古等5个产地小茴香的含量差异较小;且民勤县小茴香的挥发油含量高于其他产地,甘肃省金塔县最低。

Regulating electronic environment on alkali metal-doped Cu@NS-SiO_(2) for selective anisole hydrodeoxygenation

Lignin utilization is a potential approach for replacing fossil energy and releasing the environment pressure.Herein,we synthesized a series of novel Cu-based catalysts,Cu@NS-SiO_(2)(NS=nano sphere)and alkali metals(Na,K,Rb,and Cs)doped Cu@NS-SiO_(2),and applied them in hydrodeoxygenation reaction of anisole.High Cu dispersion was presented on all catalysts.The modification of alkali metals on Cu@NS-SiO_(2) significantly enhanced the electron density of Cu sites in the following order:Cs>Rb>K>Na,among which Cs decreased the Cu_(2)p_(3)/2 binding energy most(by 0.7 eV).Moreover,the modification did not substantially affect the geometric structure of Cu species.This regulable electronic environment of Cu sites was crucial for selective deoxygenation and inhibiting the hydrogenation of aromatic rings in anisole,and thus promoted the selectivity of benzene.Compared with Cu@NS-SiO_(2)(~59%),the highest benzene selectivity was obtained on Cs/10Cu@NS-SiO_(2) at~83%.

A型分子筛吸附苯甲醚微量水分的研究

在不同实验条件下,利用3A、4A和5A分子筛吸附苯甲醚中的微量水,并对其水含量进行测定。比较了分子筛种类、吸附温度、分子筛粒径等条件对苯甲醚中水含量变化的影响。4A和5A分子筛对苯甲醚中微量水分具有较好的吸附能力,吸附量和吸附速度相当;3A分子筛对其中水分的吸附能力较差;粒径对吸附率的影响较大,在使用吸附剂质量相同的条件下,粒径越小,吸附能力越强;物料比和吸附量与吸附速度成正相关,且随着摇床振动频率的提高,在一定范围内,分子筛吸附苯甲醚水分的速率迅速提升,但总量几乎不变。

水质苯甲醚和甲基叔丁基醚的测定方法研究

水中的苯甲醚和甲基叔丁基醚通过吹扫捕集前处理,被热脱附出来的组分经气相色谱分离后,用质谱仪进行检测。实验结果表明:苯甲醚和甲基叔丁基醚SCAN模式的方法检出限均为0.3μg/L,SIM模式的方法检出限分别为0.1,0.08μg/L,检出限能够满足生态环境标准的要求;质谱仪的离子源清洁程度影响校准曲线的线性范围;苯甲醚的盐析效应强于甲基叔丁基醚,方法适用于海水样品分析;苯甲醚和甲基叔丁基醚的正确度分别为85.0%~99.4%与88.3%~97.2%,精密度分别为2.4%~8.1%和1.7%~5.8%。该方法前处理简单易行,回收率好,可以实现一次进样,同时分析挥发性有机物、苯甲醚和甲基叔丁基醚,提高了工作效率。

用高浓度杂多酸溶液催化苯甲醚与乙酸酐的酰化反应

The catalytic behavior of concentrated heteropolyacid solution in acylation of anisole with acetic anhydride has been investigated under the reaction conditions such as molar ratio of anisole to acetic anhydride, reaction temperature and mass ratio of reactant to catalyst. When the molar ratio of anisole to acetic anhydride is changed from 2∶1 to 1∶1, the yield of methoxyacetophenone (MOAP) increases a little, but when it is changed from 1∶1 to 1∶2, the yield has a greater increase from 15% to 30%. The yield of MOAP at the reaction temperature of 363 K doubles that at 333 K. The highest yield is obtained when the mass ratio of reactant to catalyst is 12 8. The conclusion is therefore that the heteropolyacid in acetic acid can effectively catalyze the acylation of anisole with acetic anhydride, and its activity and selectivity are comparable to those of acid clay and molecular sieve.

茴香醛的直接电氧化合成研究

应用循环伏安和恒电位电解法研究了茴香醚在铂电极上直接电氧化行为.考查扫描速率、反应底物浓度、支持电解质和溶剂对该电氧化行为的影响.结果表明,茴香醚在铂电极上的氧化过程是不可逆的.在硫酸/丙酮溶液中,其响应峰电流最高,反应受扩散控制.经GC-MS检测,主要氧化产物为茴香醛,选择性为66.5%.

由碳酸二甲酯合成芳香醚的绿色工艺

综述了酚类化合物与碳酸二甲酯(DMC)甲基化反应合成芳香醚的绿色工艺。气相连续流动法和液相间歇法是2种有效的由DMC合成芳香醚的方法。在气液相转移催化和液固相转移催化的条件下,酚与DMC甲基化反应的产率和选择性均很高。酚与DMC甲基化反应的均相催化剂一般选择叔胺、叔膦、季铵盐及Schiff碱等有机碱,多相催化剂为碱金属碳酸盐、沸石、氧化铝及附载有金属盐的氧化铝和煅烧的Mg-Al水滑石。

茴香酸荧光分析法测定血清中黄芪甲甙

目的 :建立血清中黄芪甲甙含量的荧光分析法。方法 :利用茴香酸在硫酸介质中与黄芪甲甙反应产生强烈荧光的特性 ,测定血清中的黄芪甲甙。结果 :黄芪甲甙与茴香酸的反应产物的最大激发波长为Ex =32 0nm ,最大发射波长为Em =387nm。黄芪甲甙在 0 .2～ 40 .0mg·L-1范围内呈线性关系。最低检出限为 0 .0 2mg·L-1。测定样品的回收率为 98.8%～ 10 2 .4%。结论 :本文所叙述的荧光分析法具有灵敏度高、选择性好、检出限低、无干扰等优点 。

电解液添加剂对锂离子蓄电池循环性能的影响

为了改善锂离子蓄电池的循环性能 ,在EC/DEC/1.0mol/LLiClO4 电解液体系中加入微量添加剂苯甲醚。以Li金属和改性石墨为电极材料 ,循环性能测试结果表明 ,苯甲醚的加入 ,使电池的可逆比容量和充放电效率均得到提高 ,且可逆比容量的衰减速度减慢。用FTIR对首次离子嵌入过程结束后的石墨电极表面SEI(SolidElectrolyteInterface)进行组成分析 ,发现加入苯甲醚后 ,电极表面SEI中的RCO3Li含量明显减少 ,但Li2 CO3 基本不变 ,并发现有新的产物CH3OLi生成。根据以上分析结果 ,提出了苯甲醚对锂离子电池循环性能的影响机理 :在Li+嵌入石墨电极的初次过程中 ,苯甲醚和EC、DEC的还原分解产物RCO3Li发生基团交换反应 ,生成CH3OLi ,该产物能有效提高石墨电极表面SEI的稳定性 ,减少锂离子嵌入石墨过程中引起的溶剂分子共嵌入 ,从而改善电池的循环性能。