The chemical structures and performance of perovskite oxides were discussed. The oxygen and cation stoichiometry and thermal stability of the perovskite were studied. The hydrogenation and hydrogenolysis reactions which included hydrogenation of carbon dioxide were also elaborated. The analysis showed that the availability of families of isostructural perovskite-type oxides characterized by a great flexibility of the crystal to accommodate cation substitutions was useful in tailoring of efficient catalysts.