Hydrogen generation from reactions of hydrides with hydrated solids in the solid state

Abstract

The reaction of water with hydrides (hydrolysis reaction) is very attractive for onsite hydrogen generation. Instead of using liquid water like in most cases, we demonstrate that hydrogen generation from hydrolysis reactions can also occur in the solid state. By simply heating mixtures of hydrated solids and hydrides, hydrogen generation is readily achieved through the recombination from the protonic hydrogen in the hydrated solids and the hydridic hydrogen in the hydride. The composites 5CaH₂ + Na₄P₂O₇·10H₂O and NaBH₄ + H₂C₂O₄·2H₂O give attainable gravimetric hydrogen storage capacity of 2.76% at 40 °C and 2.79% at 70 °C with rapid response, respectively. The dehydrogenation temperature can be controlled by the dehydration temperature of the hydrated solids. This innovative hydrogen generation approach provides a temperature activated, easy to control solution for onsite hydrogen generation.