Compositions, methods, and apparatuses for catalytic combustion

A reactor apparatus comprising:

• a heating element comprising a plurality of plates, each plate comprising a catalytic surface having a catalyst composition applied thereon, the catalyst composition for catalytically combusting a hydrogen fuel, wherein the catalytic surface comprises a first phase including a hydrogen oxidation catalyst (HOC) and a second phase including an oxygen reduction catalyst (ORC);
• and
• a combustion cavity between each two adjacent plates;
• a conduit in contact with the plurality of plates, the conduit including:
• an inlet for receiving a heat exchange medium, and
• an outlet;
• and
• a shell surrounding the conduit and the heating element, the shell having one or more inlets for receiving the hydrogen fuel and an oxidizer;
• wherein energy released by the catalytic combustion of the hydrogen fuel is transferred to the heat exchange medium;
• wherein the catalyst composition is adapted to lower the activation energy of the combustion of the hydrogen fuel such that the reaction occurs under low temperatures;
• and
• wherein the heat exchange medium comprises water.