TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Apparatus: The power-generating unit is in the form of micro-size power source for microelectronic devices or micro-electromechanical-systems (MEMS). The electric power-generating unit further comprises a device for adding ammonia to saturate the ammonia absorbing and releasing salt with ammonia. The heating device is in the form of an electrical resistive heating device. It is provided by a heat produced by chemical reactions. The container and the device for heating are a part of a micro-size electric system being micro fabricated using processes such as mechanical grinding, chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), electron cyclotron resonance (ECR), sputtering, etching, lithographic methods such as electron beam lithography, photo lithography, or laser lithography. The reactor for dissociating ammonia contains a heterogeneous catalyst (6). The power-generating unit further comprises a combustion device where a part of the hydrogen produced in the reactor or a fraction of the ammonia and/or unreacted hydrogen from the fuel cell is oxidized for providing heat for heating the ammonia storage device or for heating the reactor for dissociating ammonia. The constituents are dimensioned to provide full balancing of the complete unit. The reactor for dissociating ammonia is a part of a micro-size electric system being micro fabricated using processes such as mechanical grinding, CVD, PECVD, ECR, sputtering, etching, lithographic methods such as electron beam lithography, photo lithography, or laser lithography. The reactor for dissociating ammonia is divided into two parts, one part operated at a low temperature that dissociates most ammonia and another part operated at a high temperature that dissociates the last present fraction of ammonia.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The ammonia absorbing and releasing salt is Mg(NH3)6Cl2. The salt is in the form of a fine powder of micro crystals or located on a porous support material. The heterogeneous catalyst comprises a support and an active phase. The active phase comprises dispersed nanoparticles of transition metals or compounds such as cobalt-molybdenum nitride (CO3Mo3N), ruthenium, cobalt, nickel and/or iron.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The ammonia absorbing and releasing salt is Mg(NH3)6Cl2. The salt is in the form of a fine powder of micro crystals or located on a porous support material. The heterogeneous catalyst comprises a support and an active phase. The active phase comprises dispersed nanoparticles of transition metals or compounds such as cobalt-molybdenum nitride (CO3Mo3N), ruthenium, cobalt, nickel and/or iron.