~(89)Ru的β缓发质子衰变性质

藉助氦喷嘴带传输系统 ,采用“p γ”符合的鉴别原理 ,成功地合成与鉴别了5 8Ni(36 Ar,2p3n)反应产生的核素89Ru ,并研究了它的 β缓发质子衰变性质 .实验给出89Ru的衰变半衰期为 (1 .2± 0 .2 )s,测定了它的β缓发质子能谱 ,提取出了89Ru经缓发质子衰变布居到子核88Mo的 2 + 和 4+ 态的相对终态分支比 (1 0 0∶6 ) .通过与统计模型计算结果进行对比 ,初步指定了89Ru基态的自旋 宇称 (5 / 2 + 或 7/ 2 ±)和质量过剩 (- 5 9.5MeV) .

Synthesis and characterization of carbon black supported Pt-Ru alloy as a model catalyst for fuel cells

A set of bimetallic Pt-Ru catalysts prepared by co-impregnation of carbon black with ruthenium(III) chloride hydrate and hydrogen hexachloroplatinate(IV) hydrate were investigated by temperature-programmed reduction (TPR), chemisorption of hydrogen, transmission electron microscopy (TEM), microcalorimetry of adsorbed CO and a structure-sensitive reaction (n-hexane conversion). The results showed that the volumetric capacities for CO and H-2 adsorption is influenced in the bimetallic Pt-Ru catalysts by the formation of a Pt-Ru alloy. The n-hexane reaction revealed that the reaction mechanism for the pure Pt catalyst mainly occurs via cyclic isomerization and aromatization due to the presence of bigger Pt surface ensembles, whereas the Pt-Ru catalysts exhibited predominantly bond-shift isomerization by the diluting effect of Ru metal addition. The differential heats of CO chemisorption on Pt-Ru catalysts fell between the two monometallic Pt and Ru catalysts extremes. (C) 2004 Elsevier B.V. All rights reserved.

Ammonia-treated activated carbon as support of a Ru-Ba catalyst for ammonia synthesis

Ammonia-treated activated carbon has been studied as a support of Ru-Ba catalyst for ammonia synthesis. It is shown that the introduction of nitrogen leads to a decrease of ammonia synthesis activity for the catalysts with a low Ba/Ru molar ratio, while no significant changes are obtained for the catalysts with a high Ba/Ru molar ratio, confirming that electronegative impurities suppress the activity in ammonia synthesis and consume part of the promoters.