The effect of alloying of palladium with silver and rhodium on the hydrogen solubility, miscibility gap and hysteresis
The effect of alloying of palladium with silver and rhodium on the hydrogen solubility, miscibility gap and hysteresis
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DOI：
10.1016/s0360-3199(00)00006-9
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发表时间：
2000-09-01
影响因子：
7.2
通讯作者：
Sakamoto, Y
中科院分区：
文献类型：
--
作者：
Kibria, AKMF;Sakamoto, Y
采用气相法研究了不同温度下Pd-5.0和10.0 at.% Ag以及Pd-5.0和10.0 at.% Rh合金中氢溶解度的变化。在这些研究中，观察到低压氢溶解度随着 Ag 含量的增加而增加，并随着 Rh 含量的增加而减少。 Pd-Rh-H 体系的平台压 (p(plat)) 显示出明显高于 Pd-Ag-H 体系的值。 p(plat)值随着Ag含量的增加而降低，而随着Rh含量的增加而增加。随着 Pd-Rh 合金中 Ag 含量的增加，Pd-Ag 合金的晶格尺寸增大，而随着 Pd-Rh 合金中 Rh 含量的增加，晶格尺寸减小，这导致了氢溶解度和 p(plat) 值的相反表现。在Pd-Ag-H体系中，随着Ag含量的增加，混溶间隙值显着减小，而随着Rh含量的增加，混溶间隙值略有增加。这种混溶间隙值随合金成分变化的变化可以从Pd-Ag和Pd-Rh合金中可用的空d带孔来理解。 Rh 含量较高的合金获得了较高的氢溶解度。研究的系统表现出显着的压力成分 (p-c) 滞后，滞后因子 (p(a)/p(d)) 和滞后导致的有用能量损失由吸收-解吸 p(plat) 值确定。随着温度、Ag 和 Rh 含量的增加，p(a)/p(d) 和由于滞后引起的能量损失逐渐减小。在给定温度下，给定 Pd-Ag-H 系统的 p(a)/p(d) 和能量损失显示出比 Pd-Rh-H 系统更低的值。 Pd-5.0 和 10.0 at.% Ag-H 和 Pd-10.0 at.% Rh-H 体系的值明显低于 Pd-H 体系，在 365 K 及以上，Pd-Ag 和 Rh-H 体系似乎比 Pd-H 体系更适合工业应用。 Pd-10.0 at.% Ag-H 系统表现出最低的滞后能量损失。 (C) 2000 年国际氢能协会。由爱思唯尔科学有限公司出版。保留所有权利。
The variation of hydrogen solubilities in Pd-5.0 and 10.0 at.% Ag and Pd-5.0 and 10.0 at.% Rh alloys has been studied at different temperatures by a gas phase method. In these studies, an increase of low pressure hydrogen solubility with increasing Ag content and a decrease of it with increasing Rh content was observed. The plateau pressure (p(plat)) of the Pd-Rh-H system showed remarkably higher value than that of the Pd-Ag-H system. The p(plat) value decreased with increasing Ag content, whereas it increased with increasing Rh content. Increase in lattice size of the Pd-Ag alloy with increasing Ag content and a decrease of it with increasing Rh content in the Pd-Rh alloy was responsible for the opposite appearance of hydrogen solubility and p(plat) value. In the Pd-Ag-H system, the miscibility gap value decreased remarkably with increasing Ag content, whereas it increased a little with the increment of Rh. Such a variation of miscibility gap value with changing the alloy component can be understood from the available vacant d-band holes of Pd-Ag and Pd-Rh alloys. Higher hydrogen solubility was attained for the higher Rh content alloy. The studied systems showed remarkable pressure-composition (p-c) hysteresis, The hysteresis factor (p(a)/p(d)) and losses in useful energy due to hysteresis were determined from the absorption-desorption p(plat) values. The p(a)/p(d) and energy loss due to hysteresis gradually decreased with increasing temperature, and Ag and Rh content. At a given temperature, the p(a)/p(d) and loss in energy of a given Pd-Ag-H system showed lower values than those of a Pd-Rh-H system. The values for Pd-5.0 and 10.0 at.% Ag-H and Pd-10.0 at.% Rh-H systems are remarkably lower than those of the Pd-H system, At and above 365 K, Pd-Ag and Rh-H systems seemed better for industrial application than the Pd-H system. The Pd-10.0 at.% Ag-H system showed the lowest loss of energy for hysteresis. (C) 2000 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.