%0 Journal Article
%T Effect of the d-Band Center on the Oxygen Reduction Reaction Activity of Electrochemically Dealloyed Ordered Intermetallic Platinum¨CLead (PtPb) Nanoparticles Supported on TiO2-Deposited Cup-Stacked Carbon Nanotubes
%J -
%D 2018
%R https://doi.org/10.1021/acsanm.8b00488
%X The electrocatalysis of PtPb ordered intermetallic nanoparticles (NPs)-deposited TiO2/cup-stacked carbon nanotube (PtPb NPs/TiO2/CS) catalysts for oxygen reduction reaction (ORR) was examined in 0.1 M HClO4 aqueous solution. The as-prepared catalyst exhibited only a low activity for the ORR, but its ORR activity was found to be largely enhanced by the electrochemical dealloying, i.e., by the dissolution of Pb via a repeating potential scan cycling between 0.05 and 1.1 V vs RHE at 100 mVs¨C1 in N2-saturated 0.1 M HClO4 aqueous solution, and to change drastically via a surface structural change of the PtPb NPs from the PtPb ordered intermetallic structure to the Pt3Pb ordered intermetallic structure and further to the Pt3Pb(core)¨CPt(shell) structure with an increase in the potential scan cycling. We also found that changing the number of the potential scan cycling leads to a change in the d-band center of the resulting catalyst, and consequently, a so-called volcano-type corelationship between ORR activity and the d-band center was found to hold for a series of the electrochemically dealloyed PtPb NPs/TiO2/CS catalysts. The maximum ORR activity was obtained for the Pt3Pb catalyst prepared by the 200 cycles of potential scan cycling, the d-band center value of which is ca. 0.2 and 0.3 eV lower than those of the Pt NPs deposited on TiO2/CS (Pt NPs/TiO2/CS) and the Pt NPs deposited on carbon black (Pt NPs/CB), respectively, being in agreement with the expectation for the ORR electrocatalysis of Pt-based catalysts ( Angew. Chem., Int. Ed. 2006, 45, 2897£¿2901)
%U https://pubs.acs.org/doi/10.1021/acsanm.8b00488