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助剂对Ni/AC催化剂甲醇羰化的影响 总被引:3,自引:0,他引:3
分别以Ni(NO3)2.6H2O、ZnAc2.6H2O、Cu(NO3)2.6H2O、(NH4)6Mo7O24及La(NO3)3.4H2O为前体,采用同时浸渍法制备了主活性组分为镍的双金属活性炭负载型催化剂,考察了Zn、Cu、Mo及La等第二金属元素对甲醇羰化合成醋酸Ni/AC催化剂的助催化作用。活性评价表明:以Mo和La为助剂时,可有效地提高甲醇转化率和羰化产物收率,Mo的添加有利于醋酸甲酯的生成,La则使醋酸的选择性提高;Zn、Cu的加入反而使甲醇转化率及羰化产物收率下降。催化剂的羰基化活性顺序为:Ni-Mo/AC>Ni-La/AC>Ni/AC>Ni-Zn/AC>Ni-Cu/AC。关于稀土元素的影响,结果是La优于Ce。 相似文献
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甲醇常压气相羰基化合成乙酸的镍基双金属催化剂的研究 总被引:2,自引:0,他引:2
从提高乙酸收率和减少副产物出发,对以甲醇气相常压羰基化合成乙酸的Ni/AC体系的第二种添加金属作了评选,Mo,Sn,Pb,La的添加可明显提高甲醇的转化率,La和Mo促进了乙酸选择性的提高,Zn的添加对生成甲烷的副反应有明显的抑制作用。在260-360℃考察了温度对羰化产物的影响,在较适宜的温度340℃,Ni质量分数为7%,La/Ni摩尔比为1:2的条件下,Ni-La/AC体系中乙酸收率达到39.18%,而Zn/Ni摩尔比为1:8时,Ni-Zn/AC双金属催化剂的羰化产物总选择性也有了较大提高。 相似文献
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考察了Ni—Pd/C双金属催化剂上催化乙醇气相羰基化合成丙酸的反应。实验结果表明,负载活性炭Ni—Pd双金属催化剂相比普通非贵金属催化剂具有很高的活性及选择性,最佳反应工艺条件为,在少量碘代乙烷存在下,压力0.15MPa,温度220℃,n(CO):n(C2H5OH)=2.0:1,乙醇液体空速1.5h^-1此时乙醇羰基化反应产物中丙酸及丙酸酯的选择性可高达96.7%,通过GC—MS对反应产物分析,分析了反应过程的机理。 相似文献
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研究了Ag/Cu/CeO2-ZrO2催化剂在富氧条件下C3H6选择性还原NO的性能,讨论了载体中铈锆比例,催化剂活性组分的负载方式以及在载体中加入适量碱土金属对催化剂反应活性的影响,结果表明铈锆比为1:3时,催化剂活性最好,NO转化率达到58.2%。在铈锆比为3:1的CeO2-ZrO2载体上,单独负载Cu的催化剂活性最好,NO转化率为53.8%。在CeO2-ZrO2载体中加入少量Ca可明显改善催化剂性能,拓宽催化剂反应温度范围。 相似文献
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Ni/PHAC催化甲醇羰基化合成乙酸工艺研究 总被引:5,自引:0,他引:5
以自制的酚醛树脂基活性炭(PHAC)负载镍为催化剂、碘甲烷为助催化剂,研究了在连续固定床反应器中催化甲醇碳基化合成乙酸的反应。探讨了反应温度、液体进料空时、甲醇与一氧化碳配比及加水量等反应工艺条件对甲醇羰基化反应及乙酸收率的影响,优化了反应的工艺条件。结果表明:反应工艺条件对甲醇羰基化反应及乙酸的收率影响较大,在系统压力为1.0MPa,反应温度558K,液体进料空时为10gcat.(mo1.h^-1)^-1,V(H20):V(CH30H)=3:100,n(CO):n(CH30H):n(CH3I)=80:40:1的条件下乙酸收率最高达到了67.1%,而羰基化产物总收率可以达到79.1%,甲醇转化率可以达到93.8%,羰基化产物总收率和乙酸收率明显高于文献报道的同类催化剂。 相似文献
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采用等体积浸渍法,分别以Zn(NO3)2,Ni(CH3COO)2,Zn(CH3COO)2,Ni(NO3)2和ZnCl2作为负载物制备了活性炭载体金属基催化剂,在自制的常压连续流动固定床反应器中,以氯化氢和甲醇为原料,在氨环境下模拟氯化铵与甲醇反应考察了不同催化剂在合成氯甲烷中的催化性能.结果表明,以活性炭为载体制备的氯化锌催化剂,在温度290~350℃,氯化氢和甲醇物质的量之比为1∶1和空速300 min-1的条件下,甲醇转化率、氯甲 烷选择性和收率较高,氯甲烷收率达到66%以上.催化剂性能稳定,且有较长的使用寿命. 相似文献
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本文研究了以固体催化剂SO42-/ZrO2催化合成醋酸正丁酯,考察了催化剂比表面、活化温度与催化活性关系,探讨了催化剂的选择性和催化工艺,确定了反应物配比、反应时间、催化剂用量等最佳工艺条件。 相似文献
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固体催化剂SO^2—4/ZrO2催化合成醋酸丁酯 总被引:2,自引:0,他引:2
本文研究了以固体催化剂SO^2-4/ZrO2催化合成醋酸正丁酯,考察了催化剂比表面,活化温度与催化活性关系,探讨了催化剂的选择性和催化工艺,确定了反应物配比、反应时间、催化剂用量等最佳工艺条件。 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