Material-Based Hydrogen Storage Technologies: A Frontier Overview of Systems, Challenges, and Machine Learning Integration

The intermittency of renewable-based power is a major barrier for long-term supply of clean energy, which necessitates the development of reliable solutions for clean energy storage and transition towards a carbon-neutral economy. Although hydrogen has emerged as a promising clean energy carrier to address this, its high compressibility requires safe, efficient and practical storage technologies for widespread deployment. Surface storage technologies for hydrogen have garnered attention due to their mobile and stationary applications, paving the way for a future hydrogen-based economy. This review provides a comprehensive review of surface hydrogen storage technologies, covering metal hydrides, metal-organic frameworks (MOFs), liquid organic hydrogen carriers (LOHCs), glass microspheres, capillary arrays, etc. Where previous reviews mostly address the chemistry behind these storage technologies, this study highlights practical integration and techno-economic assessment. Comparative analysis reveals that while LOHC and hydrides dominate in Technology Readiness Level, MOFs and carbohydrate-based systems offer high gravimetric potential, though they are currently quite costly. Other challenges like thermal management and large-scale regeneration remain critical for practical deployment. Moreover, recent advancements in Artificial Intelligence and Machine Learning offer unique insights, demonstrating their growing role in material screening, performance prediction, and the optimization of storage system designs. This review outlines the key challenges and research pathways required to support future deployment.