Conversion of KCl into KBH4 by mechano-chemical reaction and its catalytic decomposition

Abstract

Production of KBH4, in the presence of KCl, B2O3 and MgH2 by means of a mechanical reaction and a dehydrogenation kinetic, constitute the main parts of this study. Operating time and reactant ratio are considered as two parameters for the mechanical reaction to obtain the maximum yield. The production process was carried out in a ball milling reactor, and the product residue was purified with ethylene diamine (EDA) and subsequently characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and x-ray Diffraction (XRD) analyses. Optimum time for mechano-chemical treatment and reactant ratio (MgH2/KCl) were obtained as 1000 min and 1.0, respectively. Synthesized and commercial KBH4 were compared by hydrolysis tests in the presence of Co1−xNix/Al2O3 heterogeneous catalyst. Hydrogen generation rates, activation energy and order of the KBH4 decomposition reaction were obtained as 1578 mLH2min−1g−1catalystmLH2min−1gcatalyst−1, 39.2 kJ mol−1 and zero order, respectively.