Chemical and Physical Solutions for Hydrogen Storage

TLDR

Hydrogen is a promising energy carrier, but its storage—particularly for PEM fuel cell vehicles—is challenging, with options ranging from high‑pressure and cryogenic tanks to adsorptive, metal‑hydride, complex‑hydride, and borane systems. Chemical storage approaches involve reversible or hydrolytic hydrogen release with off‑board regeneration, and liquid hydrogen‑containing compounds can be reformed to generate hydrogen. The paper compares the pros and cons of each storage system.

Abstract

Hydrogen is a promising energy carrier in future energy systems. However, storage of hydrogen is a substantial challenge, especially for applications in vehicles with fuel cells that use proton-exchange membranes (PEMs). Different methods for hydrogen storage are discussed, including high-pressure and cryogenic-liquid storage, adsorptive storage on high-surface-area adsorbents, chemical storage in metal hydrides and complex hydrides, and storage in boranes. For the latter chemical solutions, reversible options and hydrolytic release of hydrogen with off-board regeneration are both possible. Reforming of liquid hydrogen-containing compounds is also a possible means of hydrogen generation. The advantages and disadvantages of the different systems are compared.