Wettability control of defective TiO_(2)with alkyl acid for highly efficient photocatalytic ammonia synthesis

Ammonia is an important chemical raw material and non-carbon-based fuel.Photocatalytic ammonia production technology as a mild alternative to the traditional Harbor–Bosch route is carried out at the air,liquid,and solid three-phase interface.Promoting the activation of N_(2),depressing hydrogen evolution reaction(HER),and increasing the local N_(2) concentration around the catalyst surface are critical factors in achieving high conversion efficiency.In this paper,we proposed that defective TiO_(2)is surfacemodified by alkyl acids with different carbon chain lengths(C_(2),C_(5),C_(8),C_(11),and C_(14))to tune the catalyst surface properties.The defect sites greatly promote N_(2) adsorption and activation.The wettability of the catalyst can be regulated from hydrophilic to hydrophobic by the length of the alkyl chain.The hydrophobic surface enhances the N_(2) adsorption and increases the local N_(2) concentration due to its aerophile.Meanwhile,it depresses the proton adsorption and HER.Overall,the nitrogen reduction reaction(NRR)is greatly promoted.Among the series of samples,they present a systematic change and have a maximal NRR performance for n-octanoic acid-defective TiO_(2)(C8-Vo-TiO_(2);Vo=oxygen vacancy).The rate of ammonia production can be as high as 392μmol·g^(−1)·h^(−1).This work provides a new strategy for efficient ammonia synthesis at the three-phase interface using photocatalyst technology.

Acidity effects of Hβ zeolite on olefin alkylation of thiophenic sulfur in gasoline

Olefin alkylation of thiophenic sulfur process was carried out in model gasoline, using Hβ zeolites with different Si/Al2 ratios as catalysts. In particular, the influence of acid properties of Hβ zeolites on its catalytic ability for the thiophene alkylation, xylene alkylation and hexene oligomerization was investigated. The results showed that the acidity of the Hβ zeolite was increased with the decrease of Si/Al2 ratio, but its catalytic ability was not always increased. In fact, it reached the maximal catalytic ability at Si/Al2 ratio of 66, and under the reaction conditions of 60 ℃, 1.5 MPa, WHSV 3.0 h^-1 and time on stream 2 h. At the ratio, the conversion of thiophene, xylene, and oligomerized hexene were 96.6%, 2.7% and 2.8%, respectively. An optimal Si/Al2 ratio exists for the catalytic performance of Hβ zeolite. By investigating the coke deposition of the used Hβ zeolite catalysts, it has been found that the optimal Si/Al2 ratio is attributed to the combined effect of the carbocation activation capability and the hydrogen transformation capability of the Hβ zeolite catalyst.

Long-chain alkanol-alkyl carboxylic acid-based low-viscosity hydrophobic deep eutectic solvents for one-pot extraction of anthraquinones from Rhei Radix et Rhizoma

Natural long-chain alkanol and alkyl carboxylic acid were used to prepare novel hydrophobic deep eutectic solvents(HDESs).These HDESs are liquid at room temperature and have low viscosity(<12.26 mPa·s),low polarity(lower than that of methanol,ChCl-based deep eutectic solvents and other reported HDESs),and low density(<0.928 g/mL).A simple one-pot method based on a novel HDES-water two-phase extraction system was constructed for the extraction of weak-polarity bioactive components,anthraquinones,from Rhei Radix et Rhizoma.This HDES-based new extraction method does not consume hazardous organic solvents and can obtain a total anthraquinone yield of 21.52 mg/g,which is close to that obtained by the Chinese pharmacopoeia method(21.22 mg/g)and considerably higher than those by other reported HDESs-based extraction methods(14.20-20.09 mg/g,p<0.01).The high extraction yield can be mainly attributed to the severe destruction of the RRR cell walls by the extraction system and the excellent dissolving ability of novel HDESs for anthraquinones.

One-pot Synthesis of Lewis Acidic Ionic Liquids for Friedel-Crafts Alkylation

Novel Lewis acidic ionic liquids containing thionyl cations and chloroaluminate anions were obtained by one-pot synthesis for the first time. Their acidities were determined by acetonitrile probe on IR spectrography. The ionic liquids were used as catalyst for Friedel-Crafts alkylation of benzene and 1-dodecene. The turnovers of l-dodecene were higher than 99%. Monoalkylbenzene selectivity was 98%, while the 2-substituent product selectivity was 45%.

Alkylation of Isobutane and Isobutene in Acidic Polyether Ionic Liquids

The Br?nsted-acidic polyether ionic liquids(ILs)with different polymerization degrees(n value)were prepared via the reaction of tetramethylguanidine and epoxy ethane,followed by successive reactions with 1,3-propane sultone and trifluoromethanesulfonic acid(TfOH).The prepared ILs were characterized by infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy,and their thermal stability was determined by thermal gravimetry.The synthesized polyether ILs coupled with TfOH were used to catalyze the alkylation reaction of isobutane and isobutene for the preparation of alkylate gasoline.The polyether ILs could improve the substrate dissolution and promote the separation of the catalyst from the products.The ideal IL(n=94)was determined.The optimized alkylation reaction conditions covered:a VTfOH/VIL ratio of 0.35,a reaction temperature of 40℃,a reaction time of 50 min,and a stirring speed of 800 r/min.The conversion of isobutene was 92.4%and the selectivity for the C8-product was 81.6%.Under optimal conditions,the catalyst life was determined and TfOH showed improved cyclic performance in the polyether ILs.After 8 operating cycles,the catalytic activity of the catalyst showed negligible decline.

Novel Synthetic Method for the Vilsmeier-Haack Reagent and Green Routes to Acid Chlorides, Alkyl Formates, and Alkyl Chlorides

An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byproduct was recovered in high yield by simple filtration. Some aromatic acids have been transformed into the corresponding acid chlorides in good yields by employing the isolated VH. Treatment of primary or secondary alcohols with VH gave alkyl formates or alkyl chlorides by depending on the reaction conditions.

A STUDY ON THE DEGRADATION MECHANISM OF PHOTOCROSSLINKING PRODUCTS FORMED BY CYCLIZED POLYISOPRENE-DIAZIDE SYSTEM UNDER THE INFLUENCE OF ALKYL BENZENE SULFONIC ACIDS

The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects of alkyl chain length and the concentration of alkyl benzene sulfonic acids on the rate of degradation reaction were discussed. It was found that in the initial stage of degradation, the cyclicity ratio and the average fused ring number did not change considerably, but the percentage of uncyclized parts content varied significantly. The suitable mechanism was supposed.

PERFLUOROOCTANESULFONIC ACID CATALYZED FRIEDEL-CRAFTS ALKYLATION WITH OLEFINS IN GAS-LIQUID PHASE

Solid superacid perfluorooctanesulfonic acid(POSA)catalyzed Friedel-Crafts alkylation of aromatic hydrocarbons with olefins in gas-liquid phase.The alkylations gave good yields with simple operation and easy work up.The amount of the catalyst used in the reactions was small and could be reused.The optimum temperature of the reactions and the effect of the amount of the catalyst used in the reactions are also discussed.

ASYMMETRIC SYNTHESIS Ⅻ:HIGHLY ENANTIOSELECTIVE SYNTHESIS OF α-AMINO ACIDS BY ALKYLATION OF THE KETIMINE FROM 2-HYDROXY-PINAN-3-ONE AND MENTHYL GLYCIN-ATE A DOUBLE ASYMMETRIC INDUCTION SYSTEM

A series of α-amino acids are obtained in 72-96% optical yields by alkylation of the ketimine derived from(+)-2-hydroxy-pinan-3-one and(-)-menthyl glycinate fol- lowed by hydrolysis of the alkylated intermediates with mineral acid.The double asymmetric induction are explained by the transition model of lithium enolate.

Preparation, Characterization and Catalytic Activity of Alkyl Benzene Sulfonic Acid Carbon-Based Acid Catalyst

Based on starch and series of alkyl benzene sulfonic acid as the materials, a novel carbon-based solid acid catalyst is synthesized using hydrothermal method. This catalyst exhibits much higher catalytic activity in the reaction of esterification of Mono-fatty alcohol polyoxyethylene maleate esters with 1,4-butanediol. The structure of carbon-based solid acid catalyst was charactered by IR and XRD, characterizations showed that this catalyst exhibited high –SO3H loading. Reusability of the carbon-based solid acid catalyst for esterification showed that after recycling five times the activity remained unchanged.

An Anionic Polymer Incorporating Low Amounts of Hydrophobic Residues Is a Multifunctional Surfactant. Part 2: Emulsification, Moisture Absorption, and Moisture Retention of Alkyl Esterified Poly-γ-Glutamic Acid

In the accompanying paper (Part 1), we showed that the fatty acid moiety and the acidity of the polysaccharide-backbone of a fatty acid-containing polysaccharide might be involved in its emul-sification, moisture absorption, and moisture retention abilities. In this study, we synthesized alkyl esterified poly-γ-glutamic acid (PGA) with various chain lengths and degrees of substitution of the alkyl moieties to examine how hydrophobic groups incorporated in the anionic polymer contribute to enhanced emulsification, moisture absorption, and moisture retention. With a low degree of alkylation of PGA, these abilities were drastically improved. To improve the moisture absorption of PGA, alkylation with a short chain length is effective in forming interspaces between PGA chains to trap water molecules. Hydrophobic-hydrophilic balance may also be important to improve the emulsification and moisture retention abilities of PGA alkylates. To the best of our knowledge, this is the first report of the relationship between the structure and the multifunctional abilities of an anionic polymer incorporated with a small amount of hydrophobic residue. PGA alkylates, as well as fatty acid-containing polysaccharides, have potential use as multifunctional surfactants throughout various industries.

Alkylation of toluene with tert-butyl alcohol over HPW-modified Hβ zeolite

An Hβ-supported heteropoly acid （H3PW12O40 （HPW）/Hβ） catalyst was successfully prepared by wetness impregnation, and investigated in the alkylation of toluene with tert-butyl alcohol for the synthesis of 4-tert-butyltoluene （PTBT）. X-ray diffraction, scanning electron microscopy, transmis- sion electron microscopy, fourier-transform infrared spectroscopy, inductively coupled plas- ma-optical emission spectrometry, the brunauer emmett teller （BET） method, tempera- ture-programmed NH3 desorption, and pyridine adsorption infrared spectroscopy were used to characterize the catalyst. The results showed that loading HPW on Hβ effectively increased the B acidity and decreased the pore size of Hβ. The B acidity of HPW/Hβ was 142.97 μmol/g, which is 69.74% higher than that of Hβ （84.23 μmol/g）. The catalytic activity of the HPW/Hβ catalyst was much better than that of the parent Hβ zeolite because of its high B acidity. The toluene conversion over HPW/Hβ reached 73.1%, which is much higher than that achieved with Hβ （54.0%）. When HPW was loaded on Hβ, the BET surface area of Hβ decreased from 492.5 to 379.6 m2/g, accompa- nied by a significant decrease in the pore size from 3.90 to 3.17 nm. Shape selectivity can therefore play an important role and increase the product selectivity of the HPW/Hβ catalyst compared with that of the parent Hβ. PTBT （kinetic diameter 0.58 nm） can easily diffuse through the narrowed pores of HPW/Hβ, but 3-tert-butyltoluene （kinetic diameter 0.65 nm） diffusion is restricted because of steric hindrance in these narrow pores. This results in high PTBT selectivity over HPW/Hβ （around 81%）. The HPW/Hβ catalyst gave a stable catalytic performance in reusability tests.

Shaped binderless ZSM-11 zeolite catalyst prepared via a dry-gel conversion method:Characterization and application for alkylation of benzene with dimethyl ether

Shaped binderless ZSM-11 zeolite catalysts were synthesized via a dry-gel conversion technique from 70ZSM-11/30 SiO;mix extrudates. 1,6-hexanediamine combined with tetrabutylammonium bromide was proved to be the best structure directing agent for the synthesis of the binderless ZSM-11 catalyst, without adding other alkaline materials. The 70HZSM-11/30 SiO;mix serials materials crystallized for different times were detected by X-ray diffraction（XRD）, nuclear magnetic resonance（NMR）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, scanning transmission electron microscopy–energy dispersive spectroscopy（STEM–EDS） techniques, and so on. In order to investigate the possible crystallization mechanism, the textural and structural properties of 70HZSM-11/30 SiO;mix serials samples were further characterized by N;adsorption–desorption. Acid properties were determined by temperature-programed desorption of NH;（NH;-TPD） and pyridine adsorption-infrared（Py-IR） measurements. In the alkylation of benzene with dimethyl ether, the serials catalysts exhibited different benzene conversions. 70HZSM-11/30 SiO;mix showed the lowest benzene conversion while sample 70HZSM-11/30 SiO;mix-6.5h synthesized only for 6.5h displayed a higher benzene conversion, even higher than the value over 70HZSM-11/30Al;O;mix. Extending the crystallization time, the obtained samples displayed the increased benzene conversion in general under the same reaction conditions. In the end, the relation of physicochemical properties with the reaction performance was investigated.

An efficient synthesis of substituted alkyl acrylates using α-keto amides

The addition of α-keto amides as a NH-acid to alkyl propiolates and dialkyl acetylenedicarboxylates in the presence of a catalytic amount of triphenylphosphine gives the corresponding substituted alkyl acrylates.

Synthesis and cytotoxicity of 28-carboxymethoxy lupane triterpenoids.Preference of 28-O-acylation over 28-O-alkylation of betulm by ethyl bromoacetate

28-Carboxymethoxy lupane tritepenoids 3 and 4 were synthesized by alkylation of betulin with the THP protected 2- hydroxyethyl iodide followed by oxidation and reduction. Direct reaction of betulin （5） or betulone （10） with ethyl bromoacetate led to 28-O-acylation, instead of 28-O-alkylation. The targeted compounds 3 and 4 were not cytotoxic at the highest concentration tested （75 μmol/L）, suggesting that elongation of the chain length at the 28-position in both betulinic acid （1） and betulonic acid （2） was detrimental to the cytotoxicity. The acylation products 28-O-bromoacetates （Sa, 8b and 11） and 28-O-methoxyacetate 13 exhibited cytotoxicity against several cancer cell lines tested.

气体分离装置碳五组分进烷基化装置加工的方法实践

为了拓宽SINOALKY硫酸法烷基化装置原料适应范围,提高烷基化油收率,解决夏季汽油蒸气压高的问题,某石化公司进行了烷基化装置掺炼少量气体分离装置碳五组分(气分碳五)的工业实践。2021年8月发现烷基化装置反应器进料管线压差异常升高0.6 MPa,通过现场逐段测压判断出堵塞部位为烷基化反应器进料管线及相关设备。经过多种方法的检测分析,判断出烷基化反应器进料管线及设备压差升高的主要原因是气分碳五中含有微量N-甲基二乙醇胺杂质,该物质与循环异丁烷中的二氧化硫反应,生成棕黄色的亚硫酸胺盐,造成进料管线及相关设备堵塞。通过创新流程设施,增设气分碳五水洗和聚结脱水流程,经过生产实践证明该气分碳五加工方法脱杂质效果良好,气分碳五水洗罐中水洗水及中和池总排口水样氮质量浓度分别稳定控制在126.2 mg/L和47.5 mg/L左右,中和池总排口水样pH稳定在6~7,在水洗污水排放指标符合要求的同时,所得烷基化油产品质量也达标,成功实现了气分碳五连续掺炼,为该气分碳五加工方法的研究和推广应用提供了强有力的理论支撑。

碳四烷基化离子液体催化剂失活机理和再生方法的研究进展

氯铝酸离子液体作为一种新型的绿色催化剂已用于催化碳四烷基化反应生产高品质汽油。然而,在长周期烷基化反应过程中,离子液体的催化活性逐渐下降,因此,明晰催化剂失活机理并恢复其催化活性对保证烷基化装置连续稳定运行至关重要。为此,综述了碳四烷基化离子液体催化剂的失活机理和再生方法,介绍了离子液体的组成、结构及其催化性能之间的关系,总结了离子液体中Br?nsted酸和Lewis酸中心的失活原因,烷基化副反应生成的酸溶油是Lewis酸性下降的主要原因。基于此,重点讨论了酸溶油的组成、结构及其与离子液体的作用机理,对比分析了从离子液体中脱除酸溶油的各类方法的优缺点,并提供了失活离子液体的活性恢复策略。

硫酸法烷基化工艺的专用过程模拟系统开发

为了实现硫酸法烷基化工艺装置的准确模拟计算,在Visual Studio2010开发环境下,采用SQLite数据库管理系统建立烷基化物性数据库;基于CAPE-OPEN标准,在已开发的通用过程模拟系统OPEN的基础上,建立烷基化反应模块,采用C++语言实现与通用过程模拟系统OPEN的集成,形成完整的硫酸法烷基化工艺的专用过程模拟系统。通过实例对所开发的模拟系统进行检验,并将计算结果与实际值进行对比。结果表明:产品质量均满足工业生产需求,计算结果与实际工业生产中的主要工艺指标基本吻合,各流股中关键组分模拟值与实际值的相对偏差都控制在2.0%以内,满足计算精度要求,说明开发的硫酸法烷基化工艺的专用过程模拟系统可进行较为准确的模拟计算。