The effect of electrochemical deposition solution’s pH on prepared platinum electrocatalystcharecteristic for oxygen reduction reaction in low temperature fuel cell systems

Nowadays, the fuel cell role in energy resources has been explicated more. At these systems, many activities are focused on improving sluggish oxygen reduction reaction at cathode especially in low temperature systems. Platinum is common electrocatalyst has been used in low temperature fuel cell systems for oxygen reduction reaction (ORR). Various methods have been used for preparing platinum electrocatalyst at cathode. One of these methods is electrochemical deposition method. The platinum is electrodeposited from electrochemical deposition solution. In this process, various parameters have effect on performance of prepared electrocatalyst. In this work the pH of electrochemical deposition solution effect on properties of electrodeposited platinum for ORR was studied. The pH of electrochemical deposition solution in presence of Britton-Robinson Buffer(0/04 M H3PO4 H3BO4; CH3COOH +Xmm 0/2M NaOH) is varied from 8 to 11. For doing electrochemical electrodeposition cyclic voltammetry method(scan rate 100 and potantioal -0.25 -1.25 (was used in a conventional three electrodesystem.The electrochemical methods like as linear sweep voltammetry and cyclic voltammetry were used for studying the fabricated electrodes for ORR at sulfuric acid solution (2.5 M) saturated with oxygen gas. According our results, the pH of electrochemical deposition solution affects on characteristic of electrodeposited platinum as electrocatalyst for oxygen reduction reaction. It has been shown the optimum result is related to buffer solution with pH 9.