This work investigated the synthesis, structural and spectroscopic characterization and analysis of the catalytic potential of SrTiO3 perovskite catalysts and Sr1-xKxTiCux/2O3 double perovskites, where x = 0.2, 0.3 and 0.5, in the preparation of biodiesel via the ethyl route. From the host structure of strontium titanate SrTiO3, solid solutions containing copper and potassium atoms with the following stoichiometries were investigated: Sr0.8K0.2TiCu0.1O3, Sr0.7K0.3TiCu0.15O3 and Sr0.5K0.5TiCu0.25O3, prepared by chemical synthesis using the Modified Polyol method. The catalytic study was carried out using heterogeneous catalysis, with the nanoparticles added to a solution containing vegetable oil and ethyl alcohol. The transesterification process was carried out in a laboratory-scale reactor, developed at LaCCeF, with a stirring system and controlled temperature. In this process, the main products formed were biodiesel and residual glycerol. Throughout the experiments, process parameters such as reaction time, catalyst concentration, temperature and degree of agitation were controlled. At the end of the reaction, it was possible to filter the