Role of chemical interaction between MgH2 and TiO2 additive on the hydrogen storage behavior of MgH2

Abstract The present study explores how the additive titania chemically reacts with magnesium hydride and influences the dehydrogenation of MgH 2 . Quantitative X − ray diffraction study of ball milled MgH 2  + xTiO 2 (x = 0.25, 0.33, 0.5 and 1) suggests that Ti substituted MgO is the main reaction product in all the product powders. Convincing evidence is obtained to conclude that Ti dissolution in MgO makes a dramatic behavioral change to MgO; passive MgO turns as an active in-built catalyst. The analysis correlating the dehydrogenation kinetics, composition of in-situ catalyst and sample durability suggests that effectiveness of Ti substituted MgO (Mg x Ti y O x+y ) as a catalyst for MgH 2 depends on the concentration of Ti in Mg x Ti y O x+y rock salt. These observations are immensely helpful for understanding the hydrogen desorption mechanism of metal oxide additives loaded MgH 2 system.