蛋白核小球藻原位催化制备生物柴油的研究

化石燃料是全球能源供应的主要来源,在过去的几十年里,由于人口和能源需求的增加,导致能源消耗和CO_(2)排放量迅速增加,加剧了全球气候变化。利用生长迅速、含油量高、对环境友好的蛋白核小球藻(Chlorella pyrenoidosa)催化转化生物柴油具有很大发展潜力,可以实现“碳中和”及可持续发展。传统的两步酯交换法制备生物柴油在经济环境上是不可行的,脱水干燥和脂质提取过程消耗了大量能源和成本,采用“一步”原位酯交换方法替代传统的两步酯交换将微藻转化为低成本高附加值产品,可以实现高生物柴油产率及高C16、C18脂肪酸甲酯组分含量,产生高质量的生物柴油,具有生态和经济效益。

电器用弹性环氧胶粘剂的研究

采用酸为催化剂均相催化合成糠叉丙酮改性环氧树脂 ,改性后的环氧树脂经胺固化后具有良好的应力 -应变关系 ,2 8d屈服压缩强度可达 92 5MPa ,压缩弹性模量为 92 3MPa ,并且具有较大的应变 (>2 5 % )。酸催化合成的糠叉丙酮改性环氧树脂具有贮存时间长、反应易控制、成本较低及固化后的固结体电性能好、表面光洁等优点。

生物柴油制备新进展

介绍了国内外酯交换制备生物柴油的最新进展。目前酯交换法制备生物柴油主要有4种方法:均相酸碱催化法、酶催化法、超临界法和非均相催化剂催化法,综合比较了4种酯交换生产方法的优缺点,同时介绍了生物柴油制备的最新进展,指出了生物柴油的发展趋势。

Iron-glutamate-silicotungstate ternary complex as highly active heterogeneous Fenton-like catalyst for 4-chlorophenol degradation

A novel iron-glutamate-silicotungstate ternary complex（FeШGluS iW） was synthesized from ferric chloride（FeI II）,glutamic acid（Glu）,and silicotungstic acid（SiW）,and used as a heterogeneous Fenton-like catalyst for 4-chlorophenol（4-CP） degradation at neutral pH value. The prepared FeШGluS iW was characterized using inductively coupled plasma atomic emission spectroscopy,thermogravimetry,Fourier-transform infrared spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,X-ray diffraction,and field-emission scanning electron microscopy. The results showed that FeШGluS iW has the formula [Fe（C5H8NO4）（H2O）]2SiW 12O40？13H2O,with glutamate moiety and Keggin-structured SiW 12O404- heteropolyanion. The catalyst showed high catalytic activity in 4-CP degradation in the dark and under irradiation. Under the conditions of 4-CP 100 mg/L,FeШGluS iW 1.0 g/L,H2O2 20 mmol/L,and pH = 6.5,4-CP was completely decomposed in 40 min in the dark and in 15 min under irradiation. When the reaction time was prolonged to 2 h,the corresponding total organic carbon removals under dark and irradiated conditions were ca. 27% and 72%,respectively. The high catalytic activity of FeI IIGluS iW is resulted from hydrogen bonding of H2O2 on the FeI IIGluS iW surface. The enhanced degradation of 4-CP under irradiation arises from simultaneous oxidation of 4-CP through Fenton-like and photocatalytic processes respectively catalyzed by ferric iron and the SiW 12O404- hetropolyanion in FeШGluS iW.

Highly efficient Rh(Ⅰ)/tris-H_8-binaphthyl monophosphite catalysts for hydroformylation of dicyclopentadiene to dialdehydes

Novel catalytic systems for the Rh‐catalyzed hydroformylation of dicyclopentadiene have been developed using tris‐H8‐binaphthyl monophosphite as ligands containing different ester substituents at the 2’‐binaphthyl position(OCOMe,OCOPh,OCOAdamantyl and OCOPhCl).The catalysts exhibited high activity(S/C=4000,TON=3286)with good to excellent selectivity towards dialdehydes.Remarkably,the Rh(I)complex bearing the ligands with chlorophenyl ester substituents led to 99.9%conversion and 98.7%selectivity for dialdehydes under relatively mild conditions(6 MPa,120°C).

Direct Synthesis of Diphenyl Carbonate with Heterogeneous Catalyst and Optimal Synthesis Conditions of the Support Prepared by Sol-gel Method

The support of catalyst for the direct synthesis of diphenyl carbonate （DPC） by heterogeneous catalytic reaction was prepared by the sol-gel method. Compared with activated charcoal, molecular sieve, porous ceramics, hopcalite, the support prepared by the sol-gel method has higher activity. The characterization of the support by X-ray diffraction （XRD） and transmission electron microscope （TEM） show that the mare crystal phase is Co2MnO4 and the average particle diameter is about 40 nm. The optimum conditions for synthesis of the support were determined by orthogonal experiments, which indicate that the proportion of Cu, Mn, and Co is the first important factor influencing the yield and selectivity of DPC. Temperature of calcination is the second one. The optimum conditions are： molar proportion of Cu, Mn, and Co being 1 ： 1 ： 1, temperature of calcination 700℃, drying at 100~C, temperature of water bath 85~C. The yield and selectivity of DPC in the process can reach 38% and 99% in the batch operation, respectively. The copper cobalt manganese mixed oxides chosen as the support contribute more to the high catalytic activity than the sol-gel method.

Synthesis of a Novel Solid Acid with both Sulfonic and Carbonyl Acid Groups and Its Catalytic Activities in Acetalization

The novel solid acid with both sulfonic and carbonyl acid groups has been synthesized from 3-((2-sulfoethoxy) carbonyl)acrylic acid and tetraethyl orthosilicate(TEOS). The catalytic activities were investigated through the acetalization. The results showed that the novel solid acid was very efficient for the reactions with the high yields. The high acidity, high stability and reusability were the key feature of the novel solid acid. Moreover, the sulfonic and carbonyl acid groups could cooperate during the catalytic process, which improved its catalytic activities. The catalyst shows recyclability, and hold great potential for replacement of homogeneous catalysts.

Structural sensitivity of heterogeneous catalysts for sustainable chemical synthesis of gluconic acid from glucose

Gluconic acid and its derivatives have been widely used in the food and pharmaceutical industries. Conventional processes that involve the conversion of glucose into gluconic acid via fermentation present several technological shortcomings as they involve energy-intensive wastewater treatment and complex enzyme separation. Greener oxidation processes over heterogeneous metal catalysts have attracted increasing attention worldwide. Au-, Pt-and Pd-based heterogeneous catalysts have been extensively used for the chemical oxidation of glucose to gluconic acid. Bimetallic catalysts synthesized by adding either noble or inexpensive metals have also presented excellent performance for the oxidations of glucose. In particular, particle size, which has been recognized as the most important factor that affect catalytic performances, could be rationally tuned by changing the types of support and ligand as well as the synthesis conditions. In this perspective review, we summarize and critically discuss the recent advances in the structural design of mono-and bimetallic catalysts for the oxidation of glucose in aqueous media. Furthermore, the challenges of developing catalysts for the green synthesis of gluconic acid have been highlighted. This review provides alternative insights for designing effective catalytic materials for the catalytic oxidation of bio-derived oxygenates over heterogeneous catalysts.

Efficient C-N Formation for Preparing α-Branched Primary Amines by Recycled Intramolecular Reactions of 1,8-Naphthosultone Using Ammonia as Nitrogen Source

Amination of tertiary and secondary alcohols using aqueous ammonia as nitrogen source was carried out by a process with recyclable intramolecular reaction of 1,8-naphthosultone, which lead to α-branched primary amines. Sulfonic resin serves as the heterogeneous catalyst for C N bond formation and protects the neighboring hydroxyl group until the required hydrolysis starts in the alkaline solution. The process can be conducted under mild conditions, no additional solvent is needed and no overreaction to secondary or tertiary amines occurs.

Reductive transformation of CO_2:Fluoride-catalyzed reactions with waste silicon-based reducing agents

CO_2 is one of the most important ＂renewable＂ carbon sources.To transform CO_2 to useful organic compounds,we examined the reactivity of two model silicon-based ＂waste＂ materials,disilanes and metallic Si powder,as reducing agents.In these reactions,fluoride salts were found to be active catalysts：CO_2 was converted to formic acid at atmospheric pressure in the presence of H_2O as a proton source and the silicon-based reducing reagents.Based on in-situ NMR and kinetics analyses,a hydrosilane and penta-coordinate Si species are proposed as the reaction intermediate and active species,respectively.

N-Heterocyclic Carbene-Pyridine Molybdenum Complex Supported over SBA-15 for Converting of Carbon Dioxide into Cyclic Carbonates

Synthesis of cyclic carbonates from carbon dioxide(CO_(2))and epoxides is an effective pathway for the CO_(2) utilization.Although various metal catalysts have been reported,it is highly desirable to develop a method for the reuse or recycling of catalysts.Herein,an N-heterocyclic carbene-pyridine molybdenum complex supported over SBA-15(Mo@SBA-15)was used as an efficient and recyclable catalyst for converting CO_(2) and epoxides into cyclic carbonates.Mo@SBA-15 in combination with tetra-butylammonium bromide(TBAB)shows high catalytic activity in the synthesis of cyclic carbonates under 100℃and 1 MPa CO_(2) pressure.In addition,Mo@SBA-15 was reused seven times without any significant activity loss.

An efficient catalytic system for the synthesis of glycerol carbonate by oxidative carbonylation of glycerol

Glycerol carbonate was synthesized by the oxidative carbonylation of glycerol catalyzed by the commercial Pd/C with the aid of NaI. High conversion of glycerol （82.2%）, selectivity to glycerol carbonate （〉99%）, and TOF （900 h-1） were obtained under the conditions of 5 MPa （Pco：Po2 = 2：1）, 140 C, 2 h. The highly active palladium species were generated in situ by dissolution from the carbon support and stabilized by re-deposition onto the support surface after the reaction was finished. Palladium dissolution and re-deposition were crucial and inherent parts of the catalytic cycle, which involved heterogeneous reactions. This Pd/C catalyst could be recycled and efficiently reused for four times with a gradual decrease in activity. Moreover, the in- fluences of various parameters, e.g., types of catalysts, solvents, additives, reaction temperature, pressure, and time on the conversion of glycerol were investigated. A reaction mechanism was proposed for oxidative carbonylation of glycerol to glyc- erol carbonate.

Research progress of polyoxometalates in catalytic oxidation

Polyoxometalates(POMs),as a class of multinuclear clusters,are polymerized of oxygen and early high-valent transition metals(e.g.,Mo,W,V and Nb).Based on the geometry of heteroatoms and the ratio of heteroatoms to coordination atoms,POMs can be classified into six classical configurations including Keggin-type,Dawson-type,Anderson-type,Waugh-type,Silverton-type,and Lindqvist-type.They exhibit the diverse structures and versatile properties,which enrich their applications in catalysis,medicine,electrochemistry,magnetism,and so on.The chemistry of POMs is an important branch of inorganic chemistry with a history of more than 200 years.It intersects with physical chemistry,analytical chemistry,structural chemistry,biochemistry,environmental chemistry,material chemistry and many other fields.Modern chemistry of POMs has developed from single POMs synthesis to controllable molecular design synthesis,from simple POMs monomer to high-dimensional,high-core and other novel structure clusters constructed with POMs as building units.Especially,POMs are considered as electron stores due to their strong ability to bear and release electrons,indicating they have redox properties.Therefore,POMs have received increasing attentions as redox heterogeneous catalysts.To resolve the problem of the high solubility of POMs,the design synthesis and performance research of functional complexes with POMs as inorganic ligands or non-coordination templates have become one of hot spots.The encapsulation of POMs into the crystalline architecture results in multifunctional hybrid materials,which combine the merits of POMs and the organic frameworks to achieve specific properties.With the increase of consciousness for environmental protection,green oxidants such as hydrogen peroxide and oxygen are utilized as main oxidants for the oxidation.The combination of POMs-based materials with environment friendly oxidants can efficiently catalyze various oxidation reactions,such as epoxidation of olefin,oxidation of sulfurcontaining compounds,oxidation of alcohols,oxidation of alkanes and so on.In this paper,an overview of recent advances of POMs in catalytic oxidation was presented.