Extensive Studies of the Electrochemical Behavior of Pt Ni/MWCNT Catalysts in Alkaline Media

Multi-walled carbon nanotubes (MWCNT) enclose properties and characteristics that are interesting and suitable for electrochemical applications. In this way, the deposition of metallic particle in the surface of MWCNT has been a topic of intense study. It is well know that bimetallic systems of Pt with other metal are of great interest due to the possibility of reduce the costs by decreasing the metal loading, and at the same time increase the properties of the electrocatalyst. In specific, PtNi/MCNT systems have proven to have high activity in different electrochemical reactions in acid media, along with good tolerance to CO poisoning. However, the main drawback is the poor stability in acidic environments. Thus, the electrochemical evaluation of these materials in alkaline media becomes an interesting field of study. Previous investigations of the research group performed in alkaline media showed that the system PtNi/MWCNT exhibited activity towards the hydrogen oxidation reaction as well as the oxidation of methanol. As a continuation, in this work a more detailed study was performed including the evaluation of different materials PtNi/MWCNT in the oxygen reduction reaction. The experimental matrix was designed to evaluate the influence of PtNi structure on the electrochemical behavior, interesting results were found.  The materials were characterized by microscopy as well as x-ray diffraction. The electrochemical tests were done in a conventional three electrodes cell, using a glassy carbon rod as working electrode, a Pt wire as counter electrode, a Ag/AgCl (KCl Sat) electrode as reference, and 1M NaOH solution as electrolyte. The results as well as the discussion will be presented at the conference.

Authors acknowledge the support to CONACyT under grant No. 213373