Recent advancement in dehydrogenation techniques for efficient hydrogen release from metal hydrides

초록

Hydrogen storage in metal hydrides offers a promising path for scalable and safe hydrogen energy systems. However, high dehydrogenation temperatures, slow kinetics, and energy inefficiencies hinder their widespread adoption. This review assesses recent advancements in dehydrogenation strategies, including thermal, catalytic, mechanical, and microwave-assisted methods, focusing on correlating mechanistic insights with performance metrics. It compiles data on activation energies, onset desorption temperatures, hydrogen release capacities, and cycle stability, highlighting enhancements such as reductions in activation energy from approximately 128.6 kJ/mol in pristine MgH2 to as low as 45 kJ/mol in engineered composites and hydrogen release rates exceeding 6 wt% within minutes under optimized conditions. The energy efficiencies of advanced techniques often exceed 65%, whereas those of the conventional methods are below 50%. This review identifies critical gaps: (i) the disparity between current dehydrogenation temperatures (170-220 degrees C) and practical targets (<120 degrees C), (ii) insufficient long-term cycling data for assessing durability under real-world conditions, and (iii) challenges in scaling laboratory-based catalytic or microwave-assisted systems to industrial platforms. These insights provide a roadmap for future research, emphasizing the integration of catalytic design, nanostructuring, and hybrid energy inputs to bridge the gap between laboratory advancements and application-ready hydrogen-storage technologies.

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