To produce the nickel foam used as catalyst (pure Ni 99,9%, not in nanoform), an open-cell foam structure of thermally decomposable material (polymers) is placed in an atmosphere containing nickel carbonyl gas. The foam structure is heated to a temperature at which the nickel carbonyl gas decomposes to form a nickel-plated structure which is then sintered to remove the decomposable polymeric structure leaving an isotropic, open-cell network of interconnected nickel wires to form the nickel foam. 7