A new quaternary ammonium heteropolyoxotungstate catalyst for propylene epoxidation to propylene oxide

A new quaternary ammonium heteropolyoxotungstant (cat.C) is prepared and characterized. And the cat.C also is an reaction-controlled phase-transfer catalyst. The catalytic system of O-2/EAHQ (2-ethylanthrahydroquinone)/cat.c is used for the epoxidation of propylene. Under the optimal conditions, the yield of propylene oxide based on EAHQ is 84.1%, the selectivity for propylene oxide based on propylene is 99.8% and the conversion of propylene based on EAHQ is 84.3%. The cat.c precipitates after the epoxidation reaction for easy separation. The cat. C is stable enough to be recycled three times without any loss in selectivity.

氮和磷在饲养-堆腐环中的循环率及有机肥料养分利用率

A five-year experiment indicated that the average loss rate of N and P in harvested products through a feeding-composting cycle was about 50% and 15%,respectively.Under high yield condition,the amount of recycled N and P from 80% harvested products and through a feeding-composting cycle in farming systems was about 3751 and 814 kghm~(-2),equivalent to 25%34% of N and 32%56% of P from chemical fertilizers applied each year to the systems.The apparent recoveries of N and P in organic manure increased with the prolongation of fertilization,indicating a synergetic residual effect existed,and was 61% and 39% in average in the five-year experiment.The use of nutrients recycled in the farming systems could not only improve soil fertility,but also increase the recoveries of nutrients and reduce the use of chemical fertilizers.

Selective hydrogenation of citral catalyzed with palladium nanoparticles in CO2-in-water emulsion

CO2-in-Water (C/W) emulsion was formed by using a nonionic surfactant of poly (ethylene oxide)-poly (propylene oxide)-poly (ethylene oxide) (P123), and palladium nanoparticles were synthesized in situ in the present work. The catalytic performance of Pd nanoparticles in the C/W emulsion has been discussed for a selective hydrogenation of citral. Much higher activity with a turnover frequency (TOF) of 6313 h(-1) has been obtained in this unique C/W emulsion compared to that in the W/C microemulsion (TOF, 23 h(-1)), since the reaction was taking place not only in the surfactant shell but also on the inner surface of the CO2 core in the C/W emulsion. Moreover, citronellal was obtained with a higher selectivity for that it was extracted to a supercritical carbon dioxide (scCO(2)) phase as formed and thus its further hydrogenation was prohibited. The Pd nanoparticles could be recycled several times and still retain the same selectivity, but it showed a little aggregation leading to a slight decrease in conversion.

Polyethylene glycol-stabilized platinum nanoparticles: The efficient and recyclable catalysts for selective hydrogenation of o-chloronitrobenzene to o-chloroaniline

In the present work, platinum nanoparticles were prepared by in situ reduction with polyethylene glycols (PEGs). The catalytic performance of Pt nanoparticles immobilized in PEGs (Pt-PEGs) is discussed for the hydrogenation of o-chloronitrobenzene (o-CNB). A high selectivity to o-chloroaniline (o-CAN) of about 99.7% was obtained with the Pt-PEGs catalysts at the complete conversion of o-CNB, which is much higher than that (83.4%) obtained over the conventional catalyst of Pt/C. The Pt nanoparticies could be immobilized in PEGs stably and recycled for four times with the same activity and selectivity. It presents a promising performance in the hydrogenation and its wide application in catalytic reactions is expected.

Catalytic oxidation of cyclohexane over Ti-Zr-Co catalysts

Ti-Zr-Co alloys have been fabricated and characterized, and their catalytic performance was discussed for the oxidation of cyclohexane with oxygen under solvent-free condition. The icosahedral quasicrystalline phase (I-phase)-forming ability of Ti-Zr-Co alloys with different compositions was discussed, and it was confirmed that I-phase could be formed as a dominating phase at the Ti-rich composition region from Ti53Zr27Co20 to Ti75Zr5Co20 in as-cast alloys. The composition and microstructure of Ti-Zr-Co alloys present crucial influences on its catalytic activity and selectivity in the oxidation of cyclohexane. The influences of some reaction parameters such as temperature, reaction time, and catalyst amounts were also investigated. Ti70Zr10Co20 alloy containing quasicrystal microstructure showed good catalytic performance with a 6.8% conversion of cyclohexane and 90.4% selectivity of cyclohexanol and cyclohexanone. It behaves as an efficient heterogeneous catalyst for the oxidation of cyclohexane and could be recycled five times without loss in activity and selectivity.

An ionic liquid based on a cyclic guanidinium cation is an efficient medium for the selective oxidation of benzyl alcohols

A novel room temperature ionic liquid (RTIL) has been prepared containing a cyclic hexaalkylguanidinium cation. The selective oxidation of a series of substituted benzyl alcohols has been carried out in it, with sodium hypochlorite as the oxidant. The RTIL acts as both phase transfer catalyst (PTC) and solvent. The ionic liquid could be recycled after extraction of the benzaldehyde product with ether.

Isolation of fucoxanthin from the rhizoid of Laminaria japonica Aresch

Fucoxanthin was extracted from the intact rhizoid of Laminaria japonica Aresch with dimethyl sulfoxide (DMSO), and then recovered from the DMSO extract by partitioning into ethyl acetate and subsequent evaporation. Some isolation conditions such as solvent volume and extraction time were screened. The quantity and quality of the extracted fucoxanthin were determined by spectral analysis (absorption spectra and fluorescence emission spectra). The results indicated that: (1) the average total content of fucoxanthin was 122.1 mu g in 1 g of fresh L japonica rhizoid; (2) in comparison with the widely used organic solvent, acetone, DMSO was much more effective for the extraction of fucoxanthin; (3) both DMSO volume and extraction time influenced extraction efficiency such as the recovery rate and purity of fucoxanthin (1 g of fresh L. japonica rhizoid treated with 4 mL DMSO for 60 min, yielded > 88% of the total fucoxanthin with purity 0.63); (4) when (NH4)(2)SO4 concentration was in the range of 0.5- 1.0 mol/L, the pigments rapidly and entirely moved from DMSO into the ethyl acetate phase; (5) the ethyl acetate and DMSO were recycled using a rotary evaporator.

长白山火山成因—物理机制和化学演化

This thesis is one of the contributions to NSFC project, “The Changbaishan Volcanism and its Links to the Northeast Asia Tectonic System”. The thesis presents our most recent works on Changbaishan Volcanism, on two aspects as (1) the chemical evolution of the Cenozoic volcanism and the physical links of magma genesis, (2) the Holocene activity of the Tianchi Volcano and risks of potential eruption. 1. Chemical evolution and physical links to the Changbaishan Volcanism Physical links to the Chanbaishan Volcanism, just like origins of most of the volcanisms in eastern China, has long been an enigma. A large scale of volcanic activity has dominated many places of eastern China in Meso-Cenozoic. Activity of these volcanisms in eastern China covers several quite different blocks, covers variety of tectonics, and covers a period of time over 200 million years. Such a large-scale and long-lived volcanism in a continental area challenges our knowledge on dynamics of the Earth’s interior. Some works on “Diwa” hypothesis and “lithospheric thinning” hypothesis present possible links between volcanisms and dynamic evolutions of the earth’s interior, but still cannot interpret where are the sources of the heat and fluid, which are essential to the volcanisms. Based on the study of this thesis, we suggest that dynamics of the deep subduction of western Pacific Plate is the critical factor to the Changbaishan Volcanism and volcanisms in NE China, and maybe even essential to most of the Meso-Cenozoic volcanisms in eastern China. In NE China, stagnant slabs flatted in the mantle transition zone (MTZ, ca. 660 km deep) transport and release significant hydrous fluid to the upper mantle. Metamorphism of the deep-subducted slabs and hence a series of mineral phases play an important role in the water transport, exchange, restore, and release. Dehydrated fluid of the wet slab ascending from the MTZ fertile the upper mantle, and also provide upward heat flow which is essential to the magma genesis. Then magma and volcanism occur with the deep subduction from Mesozoic to mordern time in eastern China. To discribe the exact chemical characteristics of the deep subduction releated volcanics is very difficult, because few researches has contributed to the chemical behaviors of fluid and trace elments in the very deep interior of the Earth, such 660 km deep, 410km or 350km where the fluid may ascend and react. However we can still find some chemical characteristics of oceanic subduction. Basalts of the Changbaishan Volcanism have siginficant characteristics of potassium rich, and even can be called a potassic igneous province. If there are only two possible ways, recycled continentical crust or oceanic crust, to fertile the mantle potossium element as we know now, it’s easy to attribute this to the deep-subducted of the west Pacific Plate. To the eastern China, fluid inclusions in mantle xenoliths from the Cenozic basalts also reveal potassium-rich characteristics. This reveals that the same potassium feritle agents may occur in the mantle sources of eastern China. 2. Holocene activiy of the Tianchi Volcano As one of the large volcanic center and complex volcanic cone, the Tianchi Volcano is a dangerous active volcano, with several Holocene eruptions. Among these eruptions, the Millennium Eruption is regardede as one of the biggist eruptions in the world in the last 2000 years. To estimate the potential danger of volcanic eruption, we discuss two essential factors, as (i) volcanic history of Holocene eruptions, including volcanic geolgy, chronnology and chemistry, (ii) state, evolution and relationship of the magma chambers in mantle and crust beneath the Tianchi Volcano.

藏东及滇东南新生代钾质岩浆作用及其深部制约

The dissertation focuses on the petrology, geochemistry of the volcanic rocks in east Tibet and southeast Yunnan. It lucubrates the Magmatic process, forming mechanism and the possible tectonic settings of the volcanic rocks. The volcanic rocks of Nangqen basin in east Tibet, Qinghai province are mainly Cenozoic intermediate-acid shoshonites. The rocks are LREE enriched and the LREE/HREE = 3～34; (La/Yb)_N = 18.17-53.59, and ΣREE 222～1260μg/g. There are no Eu anomaly, and Nb, Ta, Zr, Hf, Ti are markedly depleted. The isotopic composition is ~(87)Sr/~(86)Sr = 0.70497～0.70614, ~(206)Pb/~(204)Pb = 18.622～18.974, ~(208)Pb/~(204)Pb = 38.431～38.996, ~(207)Pb/~(204)Pb = 15.511～15.613, respectively. K-Ar age of the whole rocks and the single mineral are between 32.0-36.5Ma. Based on the trace elements and isotopic elements, we get the conclusion that the partial melting is one of the dominated forming mechanisms for the volcanic rocks in Naneqen basin. The magma did not experience the crustal contamination en route to the surface; however, the complex mixture took place in the upper mantle before the melt was formed. There are at least two kinds of mixed sources that can be identified. The basalt in southeast Yunnan province is studied. They are distributed in Maguan, Tongguan, and Pingbian County, which is located on the both sides of the Red River belt, and the ultrabasic xenolith are cursory introduced. The volcanic rocks belongs to the alkali series, which can be subdivided into trachybasalt and basanite(Ol normal molecule >5). The volcanic rocks are characteristics by high Ti and low Mg#. According to the magma calculation model, the original rocks of the basalt in southeast Yunnan province are Spinel Lherzolite in Tongguan, Garnet Lherzolite in Pingbian and Maguan, while Togguan undergoes 2-5 percent and percent of partial melting, whereas volcanism in Maguan and Pingbian was so complex to calculate. The fractional crystallization took place during the magma evoltion in southeast Yunnan. The basalt is enriched in LREE with LREE/HREE=9.23-20.19. All of the trace elements display weak Nb, Ta peak, and the depletion of Zr, Hf and Ti in Maguan and pingbian represent the presence of Garnet in the source. The composition of the isotope ratio are ~(87)Sr/~(86)Sr = 0.70333-0.70427, ~(143)Nd/~(144)Nd = 0.512769-0.512940, ~(206)Pb/~(204)Pb = 18.104-18.424, ~(207)Pb/~(204)Pb = 15.483 -15.527; ~(208)Pb/~(204)Pb = 37.938-38.560, respectively, which shows the characteristics of the HIMU type OIB. The volcanic rocks of the southwest Yunnan are derived from the enriched, OIB type mantle sources by synthesizing all the data from trace and isotope elements. It is similar to that of the volcanic rocks in Hawaii, a typical kind of the mixtures of the recycled oceanic crust plume and depleted asthenosphere. To sum up, the volcanic rocks in southeast Yunnan are formed by the intraplate hotpot volcanism.

胶东地区金矿床成矿时代及其成矿地球动力学背景-兼论壳幔相互作用与成岩成矿

Jiaodong Peninsula is the largest repository of gold in China. Varieties of studies have been involved in the mechanism of metallogenesis. This thesis is a part of the project "Study of basic geology related to the prespecting of the supra-large deposits" which supported by National Climbing Program of China to Prof. Zhou. One of the key scientific problems is to study the age and metallogenic dynamics of ore deposit and to understand how interaction between mantle and crust constrains on metallogenesis and lithogenesis. As Jiaodong Peninsula to be study area, the Rb-Sr, Sm-Nd and Pb isotopic systematics of pyrite and altered rocks are measured to define the age and origin of gold. The elemental and Sr-Nd-Pb isotopic compositions of dikes and granites was studied to implicate the source and lithogenesis of the dike and granite and removal of lithosphere and the interaction between mantle and crust in the Jiaodong Peninsula. Considering the tectonic of Jiaodong Peninsula, basic on the time and space, this thesis gives a metallogenic dynamics of gold mineralization and discusses the constraints of the interaction between mantle and crust on the metallogenesis and lithogenesis. This thesis reports the first direct Rb-Sr dating of pyrites and ores using sub-sampling from lode gold deposit in Linglong, Jiaodong Peninsula and the results demonstrate this as a useful geochronological technique for gold mineralization with poor age constraint. The Rb-Sr data of pyrites yields an isochron age of (121.6-122.7) Ma, whereas, those of ore and ore-pyrite spread in two ranges from 120.0 to 121.8 Ma and 110.0-111.7 Ma. Studies of characteristic of gold deposit, microscopy of pyrite and quartz indicate that the apparent ages of ore and ore-pyrite are not isochron ages, it was only mixed by two end members, i.e., the primitive hydrothermal fluids and wall rocks. However, the isochron age of pyrite samples constrains the age of gold mineralization, i.e., early Cretaceous, which is in good consistence with the published U-Pb ages of zircon by using the SHRIMP technique. The whole rock Rb-Sr isochron age of altered rocks indicates that the age of gold mineralizing in the Xincheng gold deposit is 116.6 ± 5.3 Ma. The Sr, Nd and Pb isotopic compositions of pyrite and altered rocks indicate that the gold and relevant elements were derived from multi-sources, i.e. dikes derived from enriched lithospheric mantle and granites, granodiorites and metamorphic rocks outcropped on the crust. It also shows that the hydrothermal fluids derived from mantle magma degassing had play an important role in the gold mineralizing. The major and trace elements, Sr-Nd-Pb isotopic data of granites and granodiorites suggest that the Linglong Granite and Kunyushan Granite were derived from partial melting of basement rocks in the Jiaodong Peninsula at post-collision of North China Craton with South China Craton. Guojialing Granodiorite was considered to be derived from a mixture source, that is, mixed by magmas derived from an enriched lithospheric mantle and crust during the delamination of lithosphere induced by the subduction of Izanagi Plate and the movement of Tancheng-Lujiang Fault. There are kinds of dikes occurred in the Jiaodong Peninsula, which are accompanying with gold mineralization in time and space. The dikes include gabrro, diabase, pyroxene diorite, gabrrophyre, granite-porphyry, and aplite. The whole rock K-Ar ages give two age intervals: 120-124 Ma for the dikes that erupted at the gold mineralizing stage, and <120 Ma of the dikes that intruded after gold mineralizing. According to the age and the relationship between the dikes and gold mineralizing, the dikes could be divided into two groups: Group I (t = 120-124 Ma) and Group II (t < 120Ma). Group I dikes show the high Mg and K, low Ti contents, negative Nb anomalies and positive Eu anomalies, high ~(87)Sr/~(86)Sr and negative εNd(t) values and an enrichment in light rare earth elements, large ion lithosphile elements and a depletion in high field strength elements. Thus the elemental and isotopic characteristics of the Group I dikes indicate that they were derived from an enriched lithospheric mantle perhaps formed by metasomatism of the melt derived from the recycled crustal materials during the deep subduction of continent. In contrast, the Group II dikes have high Ti, Mg and K contents, no negative Nb anomalies, high ~(87)Sr/~(86)Sr and positive or little negative εNd(t) values, which indicate the derivation from a source like OIB-source. The geochemical features also give the tectonic constraints of dikes, which show that Group I dikes were formed at continental arc setting, whereas Group II dikes were formed within plate background. Considering the tectonic setting of Jiaodong Peninsula during the period of gold mineralizing, the metallogenic dynamics was related to the subduction of Izanagi Plate, movement of Tancheng-Lujiang Fault and removal of lithopheric mantle during Late Mesozoic Era.

Synthesis of FeCoMnAPO-5 molecular sieve and catalytic activity in cyclohexane oxidation by oxygen

A new FeCoMnAPO-5 with AFI structure was synthesized under hydrothermal conditions and characterized by XRD, FT-IR, X-ray fluorescence, nitrogen adsorption and SEM. The oxidation of cyclohexane with molecular oxygen was studied over the catalyst at 403 K. It show d higher activity compared to FeAPO-5, CoAPO-5 and MnAPO-5. The FeCoMnAPO-5 catalyst was recycled twice without loss of activity or selectivity.

Selective oxidations on recoverable catalysts assembled in emulsions

Catalysts assembled in emulsions are found to be potentially recoverable and efficient for a number of catalytic reactions. The catalysts composed of polyoxometalate anions and quaternary ammonium cations have been designed and synthesized according to the catalytic reactions and by optimizing the structures of cations and anions. The catalysts act essentially as surfactants, which are uniformly distributed in the interface of the emulsion droplets, and accordingly behave like homogeneous catalysts. The catalysts show remarkable selectivity and activity in the oxidation of sulfur-containing molecules to sulfones in diesel and the selective oxidation of alcohols to ketones, using H2O2 as oxidant. For an example, the catalyst demonstrated over 96% efficiency of H2O2 and similar to 100% selectivity to sulfones for the selective oxidation of sulfur-containing molecules in real diesel. Moreover, the catalysts can be separated and recycled by a simple demulsification and re-emulsification.

Liquid phase oxidation of toluene to benzaldehyde with molecular oxygen over copper-based heterogeneous catalysts

We conducted the liquid phase oxidation of toluene with molecular oxygen over heterogeneous catalysts of copper-based binary metal oxides. Among the copper-based binary metal oxides, iron-copper binary oxide (Fe/Cu = 0.3 atomic ratio) was found to be the best catalyst. In the presence of pyridine, overoxidation of benzaldehyde to benzoic acid was partially prevented. As a result, highly selective formation of benzaldehyde (86% selectivity) was observed after 2 h of reaction (7% conversion of toluene) at 463 K and 1.0 MPa of oxygen atmosphere in the presence of pyridine. These catalytic performances were similar or better than those in the gas phase oxidation of toluene at reaction temperatures higher than 473 K and under 0.5-2.5 MPa. It was suggested from competitive adsorption measurements that pyridine could reduce the adsorption of benzaldehyde. At a long reaction time of 4 It, the conversion increased to 25% and benzoic acid became the predominant reaction product (72% selectivity) in the absence of pyridine. The yield of benzoic acid was higher than that in the Snia-Viscosa process, which requires corrosive halogen ions and acidic solvents in the homogeneous reaction media. The catalyst was easily recycled by simple filtration and reusable after washing and drying.