Hydrogen Production via Hydrolysis and Alcoholysis of Light Metal-Based Materials: A Review

As an environmentally friendly and high-density energy carrier, hydrogen has been recognized as one of the ideal alternatives for fossil fuels. One of the major challenges faced by "hydrogen economy" is the development of efficient, low-cost, safe and selective hydrogen generation from chemical storage materials. In this review, we summarize the recent advances in hydrogen production via hydrolysis and alcoholysis of light-metal-based materials, such as borohydrides, Mg-based and Al-based materials, and the highly efficient regeneration of borohydrides. Unfortunately, most of these hydrolysable materials are still plagued by sluggish kinetics and low hydrogen yield. While a number of strategies including catalysis, alloying, solution modification, and ball milling have been developed to overcome these drawbacks, the high costs required for the "one-pass" utilization of hydrolysis/alcoholysis systems have ultimately made these techniques almost impossible for practical large-scale applications. Therefore, it is imperative to develop low-cost material systems based on abundant resources and effective recycling technologies of spent fuels for efficient transport, production and storage of hydrogen in a fuel cell-based hydrogen economy.