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1.
Pt电极上吸附原子对仲丁醇电催化氧化性能的影响 总被引:1,自引:0,他引:1
运用电化学循环伏安和石英晶体微天平研究了HClO4溶液中仲丁醇在Pt电极及以Sb和S吸附原子修饰的Pt(Pt/Sbad和Pt/Sad)电极上的电催化氧化过程 .从电极表面质量变化可以看出 ,仲丁醇的氧化与电极表面的氧物种有着极其密切的关系 .Pt电极表面Sb吸附原子可在较低的电位下吸附氧 ,明显提高仲丁醇的氧化活性 .与Pt电极相比 ,Sb吸附原子修饰的Pt电极使仲丁醇氧化的峰电位负移约 10 0mV .相反 ,Pt电极表面S吸附原子的氧化会消耗表面氧物种 ,抑制仲丁醇的氧化 .从电极表面质量变化提供了吸附原子电催化作用的数据 相似文献
2.
IntroductionItiswellknownthatyttriumcanbeusedinmanyfields ,suchasmetallurgy ,ceramics ,lasersandelectron ics ,especiallyinfluorescentmaterialswhoseneedforhighpurityyttriumoxideisincreasing .InChina ,there sourceofyttriumisrich ,andthehighpureyttriumisbe ingo… 相似文献
3.
The title compounds, 4'-0-geranylisoliquiritigenin and 4'-0-geranylnaringenin isolated from Millettia ferruginea and Borania coerulescens respectively, were first synthesized starting from geranyl bromide, 4-hydroxybenzaldehyde and O-hydroxy acetophenones by the condensation reaction and demethoxymethylation as key steps. 相似文献
4.
This study is in keeping with the general pattern of dynamical simulations of a set of rigid three-dimensional bodies submitted to unilateral contact constraints with dry friction. An exact formulation (respecting the contact and friction laws) of the problem of predicting the system accelerations and the contact status, in further evolution is proposed. A numerical treatment of this kind of nonlinear problem is presented. This approach is applied to a simple multi-contact example, and yields results in agreement with those of analytical and numerical type, known for this example. To cite this article: C. Le Saux et al., C. R. Mecanique 331 (2003). 相似文献
5.
《Comptes Rendus Chimie》2015,18(3):293-301
Dry reforming of methane has been carried out on SBA-15 catalysts containing 5 wt% Ni and 6 wt% Ce. The effect of the order of Ni and Ce impregnation on the catalytic activity has been studied. Both metals were added using the “two-solvent” method that favors metal dispersion inside the pores. Characterizations by XRD (low and high angles), N2 sorption, SEM and TEM of the materials after metal addition and calcination indicate good preservation of the porosities and high NiO and CeO2 dispersion inside the porous channels. Reduction was carried out before the catalytic tests and followed by TPR measurements. The most active reduced catalyst was the Ni–Ce/SBA-15 sample prepared by impregnating cerium first, then nickel. All catalysts were highly active and selective towards H2 and CO at atmospheric pressure. Full CH4 conversion was obtained below 650 °C. The higher performances compared to those reported in the literature for mesoporous silica with supported Ni and Ce catalysts are discussed. 相似文献
6.
本文改进了分别由S.T.Yau,A.Ros及沈一兵给出的关于单位球面Sn+p的极小流形和复射影空间CP^n+p的Kaehler子流形及全实极小子流形的截面曲率的Pinching常数。 相似文献
7.
2-羟基-4-仲辛基-二苯甲酮肟(N530)曾用于金属钴、镍的分离[1]。但对其萃钯热力学研究尚未见报道。为此本文对N530在高氯酸介质中萃取钯的热力学进行了研究,测定了该萃取反应的表观平衡常数和热力学函数。1实验部分1.1试剂与溶液N530由中国科... 相似文献
8.
集值Superpramart的上鞅逼近 总被引:3,自引:2,他引:1
宋卫东 《数学物理学报(A辑)》2000,20(2):158-162
文中讨论了可积随机集条件期望的若干性质,在此基础上,给出了集值Superpramart的上鞅逼近.同时,证明了集值Superpramart在Kuratowski-Mosco意义下的收敛定理. 相似文献
9.
《Comptes Rendus Chimie》2015,18(3):277-282
Ni7.5/NaY catalysts were prepared using two different methods, the incipient wetness impregnation method and the “two-solvent” method. These catalysts were characterised by N2 sorption, XRD, TEM and TPR. Their activity and stability in the dry reforming of methane were tested at atmospheric pressure under an equimolar mixture of methane and carbon dioxide. Three different Ni species, very small, spherical, and layers of nickel silicate were observed by TEM. The preparation by the two-solvent method led to a better dispersion of the active phase as well as to better activity and stability. These catalysts were promoted with small amounts (0.1 wt%) of rhodium. Rhodium facilitates the reducibility and greatly enhances catalytic activity. A complete conversion (100%) for CH4 and CO2 over the Rh promoted catalyst is achieved at 584 °C and 559 °C respectively, while for the non-promoted Ni7.5/NaY catalyst, only a 60% conversion rate for CH4 and CO2 is reached at the same temperatures. 相似文献
10.
Aminolysis of 4-alkylamino- and 4-dialkylamino-2-methylthiodihydropyridines (· HI)1, 2 resp.. under various reaction-condition leads to assymmetrically or symmetrically substituted 2,4-bisalkylamino- or 2,4-bisdialkylamino-and 2-alkylamino-4-dialkylamino- or 2-dialkylamino-4-alkylaminodihydro-pyridines3, 4, 5, 6 resp. On treatment with alkali only the aminogroup in pos. 4 of the pyridines3, 4, 5, 6 is hydrolyzed and 4-hydroxy-2-aminopyridines9 are formed. Different substituted 2,4-diaminodihydropyridines3, 4, 5, 6 can also be synthesized by reaction of 4-hydroxy-2-aminopyridines (·HCl)9 with amines. Also the aminolysis of 4-alkylamino-annd 4-dialkylaminodihydropyridinthiones7, 8 resp. is described. 相似文献