Enhanced hydrogen storage properties of magnesium hydride using a KH-TiO2-Nb2O5/carbon-coated nickel nanoparticles catalyst

Magnesium hydride (MgH₂) is a promising hydrogen-storage material, but its slow sorption kinetics and high thermodynamic stability continue to limit practical implementation. In this work, we demonstrate an original and scalable approach to enhance MgH₂ performance by employing a catalyst prepared entirely from commercially available powders (KH, TiO₂, and Nb₂O₅), combined with commercial carbon-coated Ni nanoparticles (C@Ni). Unlike MXene-based catalysts widely reported in the literature, our catalyst system avoids complex and hazardous synthesis steps and enables industrially scalable processing. Two incorporation routes (one-step ball milling and a two-step mixing strategy) were evaluated. The catalyst decreased the dehydrogenation onset temperature from 321 °C to below 236 °C and reduced the activation energy from 152 to 93.8 kJ·mol⁻¹. The optimized material exhibited fast hydrogen desorption (6.38 wt% in 10 min at 300 °C) and a low-temperature absorption (5.77 wt% at 150 °C and 3.47 wt% at 75 °C), a performance not previously reported for catalyst systems derived solely from commercial precursors. Moderate cycling stability was also achieved, retaining approximately 79% capacity after 20 cycles. These results highlight the originality and practical relevance of a catalyst design strategy that enables high-performance MgH₂-based hydrogen storage without the need for laboratory-specific or non-scalable synthesis routes. • MgH 2 -1 wt% CAT-3 wt% C@Ni-MIX absorbs 5.77 wt.% of H 2 in 50 minutes at 150 °C • MgH 2 -1 wt% CAT-0.5 wt% C@Ni-MIX take 10 minutes to desorbs 6.38 wt.% at 300 °C • The desorption Ea of MgH 2 -1 wt% CAT-3 wt% C@Ni-MIX is decreased until 93.8 kJ/mol.