Abstracts Book - IMRC 2018

• SC1-P027
STUDY OF THE SYNTHESIS, CHARACTERIZATION, AND
PERFORMANCE OF POLYHEDRAL Ni-Pt NANOCATALYSTS AND
THEIR APPLICATION AS CATHODES IN PEM FUEL CELLS.
Jose Luis Reyes Rodriguez 1 , Omar Solorza Feria 1
1 Centro de Investigación y de Estudios Avanzados del IPN - CINVESTAV, Quimica, Mexico.
This work encompasses a study that addresses the synthesis, characterization,
and performance evaluation of Ni-Pt polyhedral nanocatalysts for their
application as cathodes in PEM fuel cells. The main objective of the study was
the construction of a low-power fuel cell prototype; each stage involved in its
construction, from the synthesis of catalysts to the preparation of membrane
electrode assemblies (MEA’s) is discussed. As a first stage, NiPt catalytic
materials were synthesized by a thermo-chemical reduction route using the hot
injection technique of the metal precursors in oleylamine (Oam) and/or oleic
acid (Oac) as reaction agents. A synthesis optimization was achieved by
exploring the effect that some variables like temperature, ratio of Oam:Oac, and
variation of metallic composition had on the size, morphology, and catalytic
properties of the nanoparticles. On a second stage, the synthesized catalysts
were evaluated electrochemically to determine their stability and catalytic
activity towards the oxygen reduction reaction (ORR). From those tests, the best
material was chosen for use in the preparation of membrane electrode
assemblies. On a third stage, a six monocell prototype was built. This prototype
employed the best synthesized catalyst as cathode and was electrochemically
characterized to measure its performance. This work resorted to several
characterization techniques such as TEM, SEM, EDS, XRD, and electrochemical
evaluations using RDE. Results revealed that the best polyhedral nanocatalyst
for the ORR was synthesized by using only oleylamine as a reagent. The
synthesized catalyst presented specific and mass activities greater than
commercial Pt/C-Etek by a factor of 7 and 1.5, respectively. Nanomaterials
synthesized with oleic acid possessed diminished catalytic activity. Single-fuel
cell tests revealed that the chosen cathode nanocatalyst achieved a current
density of 770 mA cm -2 and a power density of 308 mW cm -2 at 0.4 V.
Acknowledgment:
The authors gratefully acknowledge the financial support of the Mexican council
for science, Consejo Nacional de Ciencia y Tecnología, CONACYT, (grant 245920