The future need for hydrogen as an industrial commodity and possibly as a fuel has recently been widely discussed. 1 3 At present, nearly all of the hydrogen consumed in the world is produced by reacting hydrocarbons with water. As the supply of hydrocarbons diminishes, the problem of producing hydrogen from water alone will become increasingly important. Furthermore, producing hydrogen from water is a means of energy conversion by which thermal energy from a primary source, such as solar or nuclear fusion or fission, can be changed into a easily transportable and ecologically acceptable fuel.