A direct electrochemical route from oxides to TiMn2 hydrogen storage alloy

This study is for investigating the direct electro-deoxidation of mixed TiO2-MnO2 powder to prepare TiMn2 alloy in molten calcium chloride. The influences of process parameters, such as sintering temperature, cell voltage, and electrolysis time, on the electrolysis process were examined to investigate the mechanism of alloy formation. The composition and morphology of the products were analyzed by XRD and SEM, respectively. The electrochemical property of TiMn2 alloy was investigated by cyclic voltammetry measurements. The results show that pure TiMn2 can be prepared by direct electrochemical reduction of mixed TiO2/MnO2 pellets at a voltage of 3.1 V in molten calcium chloride of 900 degrees C for 7 h. The electro-deoxidation proceeds from the reduction of manganese oxides to Mn, which is reduced by TiO2 or CaTiO3 to form TiMn2 alloy. The cyclic voltammetry measurements using powder microelectrode show that the prepared TiMn2 alloy has good electrochemical hydrogen storage property. (C) 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.