[Pt]	Pt loading
a	lattice parameter
b	Tafel slope
C	bulk concentration of oxygen molecules
D	diffusion coefficient of oxygen
E r	reversible potential for the electrode
F	Faraday’s constant
I	test current
j	current density
j 0	exchange current density for the ORR
j k	kinetic current density
l	number of layers and
m	parameters related to the mass transport limitation
n	parameters related to the mass overpotential
ne	number of exchanged electrons in the reaction
N S	number of surface atoms
N T	total number of atoms
Q H	charge exchanged
q H	charge required for the monolayer adsorption of H2 on Pt surfaces
R	total resistance
s	probe spacing
t	specimen thickness
V	measured voltage