A fuel for splitting water into hydrogen and an oxide component comprises a substantially solid pellet formed from a solid-like mixture of a solid-state source material capable of oxidizing in water to form hydrogen and a passivation surface layer of the oxide component, and a passivation preventing agent that is substantially inert to water in an effective amount to prevent passivation of the solid-state material during oxidation. The pellets may be introduced into water or other suitable oxidizer in a controlled rate to control the rate of reaction of the source material with the oxidizer, and thereby control the rate of formation of hydrogen. Methods are described for producing the solid-like mixture in varying weight percent of source material to passivation preventing agent.