Recording of hydrogen evolution—a way for controlling the doping process of sodium alanate by ball milling

• Published in: Journal of alloys and compounds Vol. 370; no. 1; pp. 104 - 109
• Main Authors: Bellosta von Colbe, J.M., Bogdanović, B., Felderhoff, M., Pommerin, A., Schüth, F.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 12.05.2004; Elsevier
• Subjects: Ball milling; Condensed matter: structure, mechanical and thermal properties; Deformation and plasticity (including yield, ductility, and superplasticity); Exact sciences and technology; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Monitoring of gas evolution (absorption); Physics; Sodium alanate for hydrogen storage; Monitoring of gas evolution (absorption); Ball milling; Sodium alanate for hydrogen storage; Gas absorption; Stoichiometry; Hydrogen storage; Ball mill; Doping; Sodium; Preparation; Viscoplasticity; Recording material; Catalyst activity; Flow stress
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2003.09.146

A simple equipment was developed which allows to monitor gas evolution or absorption occurring in the course of a ball milling process. The equipment has been applied to characterize via hydrogen evolution the reduction process of metal halides used as doping agents in the preparation of sodium alanate hydrogen storage materials. The gas flow curves resulting from the measurements ( Figs. 2–4) deliver useful informations concerning the rate, progress and completion of each of the involved reduction process, so that the stoichiometry of the underlying chemical reactions could be conceived or confirmed ( Eqs. (3)–(7)). In the preparation of sodium alanate hydrogen storage materials, the presented method can help to find out ball milling parameters necessary to produce an optimal catalytic activity of a dopant.