Abstracts Book - IMRC 2018

• SF3-O047
ON THE MECHANISM RESPONSIBLE FOR THE CATALYTIC
ACTIVITY OF PLATINUM FOR OXYGEN REDUCTION AND
HYDROGEN EVOLUTION REACTIONS
Mahmoud Reda 1
1 Canadelectrochim, R&D, Canada.
Pt is required as a catalyst for both oxygen reduction reaction (ORR) and
hydrogen evolution reaction(HOR) . This means that any type of fuel cell or a
configuration to split water into hydrogen and oxygen require platinum as a
catalyst. Currently, much of the cost of fuel cells arises from the need for
precious metal catalysts – primarily Pt – to drive the necessary electrochemical
reactions. For example, the cost of the Pt alone in a PEFC for a small 100 kW car
is higher than the cost of an entire 100 kW gasoline engine. And there is another
problem. During the course of the lifetime of a fuel cell, the Pt cathode suffers
from oxidation, migration, loss of active surface area, and corrosion of the
carbon support. Impurities, as well as methanol diffusing from the anode side
of DMFCs, can also ‘poison’ the catalyst, reducing its activity and efficiency. So
not only do fuel cells rely on a high-price commodity for their operation, they
also require a high density of that expensive material. Understanding the
mechanism responsible for such material is necessary to reduce the cost of fuel
cells and water splitting configuration. It is well known that the crystal structure
of platinum is an face centered cubic (FCC). In this case the lattice constants
which influence the bandgap energy are equal a. In fact it may be that the
bandgap energy is inversely proportional to the inverse of the a(3) [1] Based on
the idea that the lattice constant influence the bandgap and the fact that the
bandgap energy is the energy required to move the bonded valence electrons
to free conduction band which is the energy required to do the rate limiting step
for the ORR or HER, a mechanism for the effect of platinum will be derived.
Reference
[1] R. Da1ven, Phys. Rev. B, 8,12 1973
[2]D. Bensaid , International Journal of Metals, 2014 (2014), Article ID 286393, 7
pages
Keywords: Platinum, Oxygen Reduction Reaction, Hydrogen Evolution Reaction
Presenting authors email: corrosion555@gmail.com