The impact of graphene substrate-Pd nanoparticle interaction on the O, OH, and OOH adsorption that is directly related to the electrocatalytic performance of these composites in oxygen reduction reaction (ORR) has been investigated by first-principles-based calculations. The calculated binding energy of a Pd 13 nanoparticle on a single vacancy graphene is as high as -6.10 eV, owing to the hybridization between the dsp states of the Pd particles with the sp 2 dangling bonds at the defect sites. The strong interaction results in the averaged d-band center of the deposited Pd nanoparticles shifted away from the Fermi level from -1.02 to -1.45 eV. Doping the single vacancy graphene with B or N will further tune the average d-band center and also the activity of the composite toward O, OH, and OOH adsorption. The adsorption energies of O, OH, and OOH are reduced from -4.78, -4.38, and -1.56 eV on the freestanding Pd 13 nanoparticle to -4.57, -2.66, and -1.39 eV on Pd 13/single vacancy graphene composites, showing that the defective graphene substrate will not only stabilize the Pd nanoparticles but also reduce the adsorption energies of the O-containing species to the Pd particle, and so as the poisoning of the ORR active sites. © 2011 American Chemical Society.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported by the Special Academic Partner GCR Program from the King Abdullah University of Science and Technology. X.L. would also like to thank NSFC of China (11174045, 21103015), Chinese Scholarship Council (2009606533), Young Teacher Training Program of Dalian University of Technology (1000-893238, 1000-893374), and Fundamental Research Funds for the Central Universities (DUT11LK19) for financial support.
ASJC Scopus subject areas
- Surfaces, Coatings and Films
- Physical and Theoretical Chemistry
- Electronic, Optical and Magnetic Materials