Theoretical study of particle size effect on oxygen reduction reaction on Pt catalyst

摘要

Particle size effect on the oxygen reduction reaction on Pt catalysts was studied by a first principles-based mean-field model. Elementary redox potentials were approximately described by Kelvin equations and were used to estimate elementary reaction rates on nano-particles. Results indicated that the specific activity decreases with the decrease in the particle size because increased Pt-0 surface coverage hinders the ORR. The mass activity becomes maximal at a diameter of 2 nm as reported in experimental studies.