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141.
XIE Mao-Song YANG Xu CHEN Wen-Heng TAO Long-Xiang WANG Xuc-Lin XU Gui-Fen 《天然气化学杂志》1996,5(3):210-221
IntroductionMethancisthcmaJorcomponcntofnaturalgasanditscatalyticconvcrsiontodcsiredchemicalproductsorliquidfiJcIisnotonl}'apromisingapproachtotheutilizationofnaturalgasrcsourccbutalsoagrcatsubjcctforcatalysissciencctt'hichdcaIst"iththcactivationofsmallmolcculesThcx"orldrcscrvcofnaturalgashasbccnexplorcdasaboutl382562xl()8m3IllTheMTGprocessdcvclopedbythcMobilcorpcangctliquidfuelfrommethancthroughsteamreformingofmethanctoproduccsynthcsisgaswhichisassociatedt'ithamaJorityofthecostsofthcprocc… 相似文献
142.
采用聚乙烯醇对碳纳米管表面进行改性,通过化学沉淀法将Al(OH)3均匀沉积在碳纳米管表面,然后在氮气气氛下于500 ℃煅烧2 h,制备出氧化铝/碳纳米管复合材料。采用TEM、TG、DTA、XRD、IR、氮吸附脱附(比表面积及孔结构分析)等对氧化铝/碳纳米管复合材料进行表征,结果表明:未经聚乙烯醇改性的碳纳米管,氧化铝与碳纳米管相互分离;经聚乙烯醇改性的碳纳米管,氧化铝与碳纳米管结合良好。经聚乙烯醇改性的碳纳米管表面均匀覆盖一层聚乙烯醇膜,通过聚乙烯醇的吸附作用, Al(OH)3沉积在碳纳米管表面形成一层连续的覆盖层。 相似文献
143.
不同沉淀剂制备的Ag/TS-1催化丙烯直接气相氧化合成环氧丙烷 总被引:3,自引:0,他引:3
在423K、常压固定床石英反应器中,以丙烯直接气相氧化为探针反应,考察了催化剂制备方法、沉淀剂的种类和浓度对制备的Ag/TS-1催化剂催化性能的影响,采用TEM,XRD和UV-Vis等表征手段对Ag/TS-1催化剂进行了分析.结果表明,沉积-沉淀法是最佳的催化剂制备方法,但浸渍法也可制得具有环氧丙烷选择性的催化剂.K2CO3是一种良好的沉淀剂.以K2CO3为沉淀剂,硅钛比为64的TS-1为载体制备的Ag/TS-1催化剂上的丙烯转化率为1.72%,环氧丙烷选择性为98.2%.少量单质银的存在有利于环氧丙烷的生成,除银粒子的分散状态外,银粒子与载体TS-1间的相互作用对提高催化剂的选择性具有决定性作用. 相似文献
144.
Sb/ZSM-5 was obtained by solid-state reaction with the mixture of Sb2O3 and zeolite HZSM-5 under a dry nitrogen flow at 773 K. Characterization of the treated zeolite was undertaken with XRD, 27Al MAS NMR, BET, TGA and FT-IR. The results revealed that part of the antimony oxides migrated into the channels of zeolite, and decreased the Brönsted acid sites in Sb/ZSM-5 remarkably. The other part of antimony oxides together with the amorphous alumino-silicate in the products distributed on the external surface of zeolite ZSM-5 and modified it, while the framework of ZSM-5 in crystal phase was retained. The structure of occluded antimony oxide inside the channels of ZSM-5 was studied by XRD Rietveld method. The result showed that their structure can be described as a chain of non-perfect [Sb5O5(H2O)2]n5n+, which is parallel to the straight channel of ZSM-5. There is about 0.6 [Sb5O5(H2O)2]5+ unit in every cell of the ZSM-5 on an average. 相似文献
146.
147.
载气气氛对Co/MgMoO4催化剂CVD法高效合成碳纳米材料的影响 总被引:2,自引:0,他引:2
High yield and quality mutli-walled carbon nanotube (MWNT) bundles and carbon nanofibers were synthesized by catalytic decomposition of methane over Co/MgMoO4 catalyst at 1 000 ℃. TEM studies showed that the products were mainly carbon nanofibers without carrier gas and were all MWNT bundles with hydrogen or nitrogen as carrier gas. Thermal gravimetric analyses (TGA) on the raw product indicated that the purity of MWNT was higher than 95wt%. The growth mechanism of carbon nanofibers and MWNTs was also discussed. 相似文献
148.
The solid diffusion coefficient of lithium-ion in LiCoO2 cathode material has been investigated by the capacity intermittent titration technique (CITT) at different voltages and at different charge/discharge cycles. By SEM, XRD and FTIR techniques, the structure of LiCoO2 was studied before and after charge-discharge cycles, and the relationship between solid diffusion coefficient and crystal structure was further discussed. CITT results show that the value of Li+ solid diffusion coefficient of LiCoO2 is about 10-12 cm2·s-1. During the whole charge-discharge cycles, the Li+ solid diffusion coefficient decreased within the voltage of 4.0~4.3 V, which is attributed to the change of the structure of LiCoO2. 相似文献
149.
The investigated materials have similar routes of thermal decomposition; i.e. they lose their crystal water first, then at
a higher temperature their structural one. At least the result TiP2O7 goes through a phase change at about 1000 K. The amorphous titanium phosphate lost its crystal and structural water at higher
temperature than those of crystalline forms. Both α- and γ-titanium phosphates and also their transition metal containing
forms have layered structure. In case of α- and γ-forms after the loss of crystal water a phase change occurs which is followed
by the decomposition of the molecule. Various transition metals containing γ-titanium phosphates lose their crystal water
at the same temperature, with the exception of Ni containing ones. The process is finished in this case at temperature 90
K higher than that of the others.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
150.