NOVELTY - A non-noble metal and/or its oxide based nanoparticle catalyst comprises support prepared by coating inorganic porous material with organic material. The support is deposited with ions by impregnation and heat treatment reducing or oxidant depending on the desired active metallic phase in form of metal and/or oxide. The non-noble metals or their oxides are transition series. The inorganic porous material is metallic oxides alumina. The organic material contains carbon, nitrogen, oxygen, two aromatic or heteroaromatic groups and conjugated double bond.    USE - Non-noble metal and/or its oxide based nanoparticle catalyst used for ammonia decomposition for producing hydrogen as ammonia reformers of hydrogen powered systems, such as internal combustion engine and fuel cells (claimed).    ADVANTAGE - The catalyst has increased stability even after prolonged treatments at high temperatures.    DETAILED DESCRIPTION - Non-noble metal and/or its oxide based nanoparticle catalyst comprises support prepared by coating inorganic porous material with organic material and followed by pyrolysis. The support is deposited with ions by impregnation and heat treatment reducing or oxidant depending on the desired active metallic phase in form of metal and/or oxide at oxidation grade zero. The non-noble metal or its oxide is transition series. The inorganic porous material is metallic oxides alumina, zirconium dioxide (ZrO2), cerium oxide (CeOx), magnesium oxide (MgO), magnesium-aluminum oxide (MgAl2O4), lanthanum oxide (La2O3), silicon dioxide (SiO2), and/or yttrium oxide (Y2O3). The organic material contains carbon, nitrogen, oxygen, two aromatic or heteroaromatic groups and conjugated double bond. An INDEPENDENT CLAIM is included for a process of preparing catalyst by forming mixture of inorganic porous material and organic material in solvent to dissolve at 20-90 degrees C, removing solvent, drying; carrying out heat treatment in inert atmosphere at 400-1000 degrees C, depositing metal ions of non-noble metals by classical impregnation at 20-90 degrees C, and drying; and carrying out heat treatment in the presence of hydrogen to obtain active metal phase in form of metal at zero oxidation grade, and oxygen to obtain active metal phase in form of metal oxide.