Kinetics and modeling study of magnesium hydride with various additives at constant pressure thermodynamic driving forces

被引：22

作者：

Sabitu, S. T. ^{[1
]}

Fagbami, O. ^{[1
]}

Goudy, A. J. ^{[1
]}

机构：

[1] Delaware State Univ, Dept Chem, Dover, DE 19901 USA

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2011年 / 509卷

关键词：

Hydrogen absorbing materials; Metal hydride; Magnesium hydride; DEHYDRIDING KINETICS; HYDROGEN SORPTION; NB2O5;

D O I：

10.1016/j.jallcom.2010.11.174

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

In this research a comparison was made of the reaction kinetics of MgH2 ball milled with 4 mol% of TiH2, Nb2O5 or Mg2Ni. This comparison was made using a novel procedure in which the ratio of the equilibrium plateau pressure (P-m) to the opposing pressure (P-op) was the same in all cases. TPD analysis showed that the addition of 4 mol% of the various additives to MgH2 resulted in a reduction of the onset temperature of MgH2 by as much as 120 degrees C. Kinetic data showed that the reaction rates with additives are in the order: TiH2 < Mg2Ni < Nb2O5. These data were fitted to models for a moving boundary mechanism, a diffusion-controlled process, and nucleation and growth. It was found that a moving boundary mechanism best fit the data and most likely controlled the reaction rates. Kissinger plots showed that the activation energies for the mixtures were in the order: TiH2 > Mg2Ni > Nb2O5. (C) 2010 Elsevier B.V. All rights reserved.

引用

页码：S588 / S591

页数：4

共 13 条

[1] Fast hydrogen sorption kinetics of nanocrystalline Mg using Nb2O5 as catalyst [J].