Improving hydrogen storage performance of MgH2 by LaNi0.8Co0.2O3 synthesized via sol-gel technique

MgH 2 is deemed a promising hydrogen storage medium due to its high theoretical capacity (7.6 wt%). However, its commercialization remains constrained by critical scientific hurdles, including elevated absorption/desorption temperatures, inferior kinetics, and cycling instability. Catalytic engineering enables comprehensive performance enhancement of MgH 2 . Herein, functionalized rare-earth perovskite nanoparticles were synthesized via sol-gel route as catalysts to enhance the comprehensive hydrogen storage properties of MgH 2 . The catalyzed MgH 2 exhibited a drastically reduced initial dehydrogenation temperature from 320 to 214 °C, and enabling room-temperature hydrogen absorption. Subsequently, over 5 wt% reversible hydrogen absorption/desorption was achieved at 175/320 °C within 2 h. DSC analysis further revealed a notable reduction in dehydrogenation activation energy (from 128.44 to 98.62 kJ mol −1 ) and optimized dehydrogenation kinetics. Additionally, 5.5 wt% hydrogen release is retained after the 10th dehydrogenation cycle,and the cycle performance is well improved. Moreover, the modification mechanism was studied by multiple means of characterization. The results indicate that the incorporated LaNi 0·8 Co 0·2 O 3 interacts with MgH 2 during dehydrogenation, in-situ forming active catalytic phases (e.g., LaH 3.01 , Ni, Co, and Mg 2 Ni). The in-situ generation of diverse active phases establishes a multi-catalytic environment for MgH 2 via “hydrogen spillover” and “hydrogen pump” effects, synergistically enhancing its hydrogen storage capabilities. This experiment provides a reference value for promoting the commercial application of MgH 2 and designing more efficient catalysts.