Abstarct: Fuel cells have been of great interest in recent years due to the direct conversion of chemical energy into electrical energy. Among the different types, methanolic fuel cell and direct formic acid are suitable option for energy production in portable devices, which have attracted significant interests researches. Among the most common catalysts used in the anode part of fuel cells, platinum has low voltage and very high current density. Although platinum is currently the most common catalyst in fuel cells, its high price is one of the serious obstacles in the commercialization of these types of cells. Therefore, in the first part of the thesis, solutions are presented to increase the efficiency of the platinum catalyst in order to reduce its consumption, which results in decrease of the price of methanol and formic acid fuel cells. For this purpose, nano technology has been used to further increase the efficiency of platinum. And PtNPs-GA nanocatalyst was prepared by gallic acid through a simple one-step process. Gallic acid is one of the available and cheap materials that was used for the first time in terms of efficiency and environmental issues as a reducer and stabilizer with a very good ability to successfully reduce platinum. Its structure, size and morphology were investigated by field emission scanning electron microscope (FESEM) and X-ray diffraction spectroscopy (EDX). Also, platinum nanoparticles synthesized with gallic acid were further investigated by Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectrophotometer. The electrochemical activity of the modified electrode for the oxidation of methanol and formic acid in acidic environment was investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance techniques. In the second part of this thesis, alkaline electrolyte was used in fuel cells instead of acid electrolyte in order to eliminate platinum consumption and use non-platinum mextals e.g. gold as electrocatalysts and increase the efficiency of fuel cells. that the function of the cell can be significantly improved, and its toxicity and final cost are also lower than the acidic environment. For this purpose, for the first time, a simple, inexpensive and environmentally friendly chemical method was used to prepare gold nanoparticles for the electrooxidation of ethylene glycol (EG) molecules on the surface of a glass electrode in an alkaline environment. Its structure, size and morphological composition were investigated by FESEM and EDX. Also, gold nanoparticles synthesized with gallic acid were analyzed by UV-Visible and FTIR analysis. This research showed that changing the molar ratio of gold salt and gallic acid (GA-AuNPs) plays an important role in controlling and distributing the particle size. In such a way that the average diameter of GA-AuNPs (1:1) decreased from 73.3 nm to 22.6 nm and their size distribution decreased from 32.2 nm to 6.5 nm. The electrochemical activity of the modified electrode for EG oxidation in alkaline medium was investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance techniques. At the end of the research, in the continuation of the effort to remove platinum and also usage cheaper mextals at the same time, copper and palladium nanoparticles were used as electrocatalysts to replace platinum in the methanol electrooxidation reaction in alkaline environment, which leads to the increase of electrocatalytic activity and the reduction of the total price and the increase of the commercialization of the fuel cell industry. In addition, the role of reduced graphene oxide as a substrate in this type of synthesized electrocatalyst was investigated. Reduced copper-palladium-graphene oxide nanostructure was prepared by a simple electrochemical method on the surface of glassy carbon electrode. In order to prepare RGO/GCE, a suspension of graphene oxide was dropped on the surface of the glassy carbon electrode and a thin film was formed on the surface by applying a constant and negative potential. Then, copper nanostructure was deposited on RGO/GCE surface using electrochemical method. Finally, Pd-CuNDs-RGO/GCE was prepared using the method of spontaneous transfer between copper and palladium nanostructures. The structure and morphology of the prepared electrode were investigated by FESEM and EDX. The electrochemical activity of the modified electrode for the oxidation of methanol in alkaline environment was investigated by cyclic voltammetry, chronoamperometry and impedance techniques.