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为进一步克服常规一氧化碳催化偶联反应的技术性不足,作者课题组在热催化反应的基础上探索性引入了人工光源,通过光催化和热催化对一氧化碳偶联反应的共同作用,降低反应温度并提高产品的收率和选择性。我们采用浸渍法制备了负载量为1%的二氧化钛-氧化铝负载的钯催化剂Pd-TiO2/Al2O3,并将该催化剂用于光-热气相催化一氧化碳与亚硝酸甲酯偶联生成草酸二甲酯/碳酸二甲酯。研究证明在60~110℃时,引入的人工光源能够将主要产物草酸二甲酯的产率提高20%~50%,选择性提高10%~30%,表明在一氧化碳偶联反应中,光-热协同催化效应能够有效提高催化剂的反应活性,同时调控产物的选择性。相关协同催化机理的研究目前正在展开中。 相似文献
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气相法CO催化偶联制取草酸二甲酯的研究 总被引:10,自引:1,他引:9
本文对气相法CO催化偶联制取草酸二甲酯新工艺进行了实验研究。在气相流动循环系统中,采用固定床反应器,对研制的两种新型催化剂A_3、A_4进行了偶联反应催化性能测定。实验结果表明,草酸二甲酯的空时收率与催化剂的活化温度、原料气的浓度及反应温度有关。通过对实验数据的关联,得到草酸二甲酯空时收率y DMO与原料气浓度的幂数型关系为: y DMO=k·C_(CO)~α·C_(MN)~β式中:α=1,β=2.5,k=3.26×10~4。C_(CO)·C_(MN)分别为CO和亚硝酸甲酯的浓度。 相似文献
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李珏 《精细化工原料及中间体》2014,(9)
正20世纪80年代以来,随着C1化学化工的发展,草酸酯法合成乙二醇成为研究的热点。草酸酯合成法主要原料为NO、CO、H2和醇类,反应原理是NO与O2反应生成N2O3,再利用醇与N2O3反应生产亚硝酸酯,CO与亚硝酸酯在催化剂作用下氧化偶联得到草酸二甲酯,草酸二甲酯再经过催化加氢制得乙二醇。近年来,我国在草酸酯加氢合成乙二醇技术开发方面取得了长足进展。本文从催化剂、生产工艺、设备以及产品纯化等方面概述了近年来我国草酸酯加氢合成乙二醇专利技术研究进展。 相似文献
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双金属钯催化剂上CO气相偶联制草酸酯的研究 总被引:7,自引:1,他引:6
在固定床反应器中对钯系催化剂上CO气相催化偶联制草酸二乙酯和草酸二甲酯的空时收率、选择性和CO的转化率进行了实验研究.结果表明在双金属钯催化剂上,草酸二甲酯的空时收率高于草酸二乙酯的空时收率。在亚硝酸酯与CO进料摩尔比为1:1时,生成草酸二甲酯的最佳反应温度为130℃,生成草酸二乙酯的最佳反应温度为120℃。并对亚硝酸酯在该催化剂上的分解规律进行了实验研究。 相似文献
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煤制乙二醇合成工艺中CO催化偶联合成草酸二甲酯的过程是典型的碳一化学。其中NOx在草酸二甲酯的合成过程中循环利用,只需要在开车阶段对合成系统进行补入。在不同的煤制乙二醇工艺技术流程当中NOx的补入方法是有所不同的。介绍了现阶段工业化生产稳定运行的草酸二甲酯合成装置中NOx补入方法和榆林化学180万t/a煤制乙二醇项目草酸二甲酯合成装置中NOx补入方法,同时对几种不同的补入方法进行比较,分析这几种补入方式的优点和不足之处。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria. 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively.
There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized.
High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without
the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of
fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to
achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic
SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve
F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender
particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing,
and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing
or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually
preserves suspension stability during freezing.
Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago,
IL. Tied for first place in The John A. Gordon Best Paper Competition. 相似文献
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Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US
In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae
and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted
in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures
(release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species
(Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species
to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were
exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of
separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles
from the southeastern region of the US. 相似文献
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Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed. 相似文献
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
收集了2007年7月~2008年6月世界塑料工业的相关资料,介绍了2007~2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍. 相似文献
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
收集了2005年7月~2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。 相似文献