Shape Reconstruction from Commercial Pt/C to High-Index Pt/C for Advanced Electrocatalysts

Pt-based materials with high-index facets (HIFs) are highly regarded as efficient electrocatalysts, because of their abundant active step sites. Nevertheless, it is still a significant challenge to control the size to match that of commercial Pt/C (∼4 nm). Here, Pt THH(210)/C with an average size of ∼6 nm is successfully synthesized by employing bismuth (Bi) as a structural modulator to reshape commercial Pt/C. In-situ Fourier transform infrared spectroscopy (FTIRS) with formic acid and CO probes demonstrate that Bi is effectively removed from tetrahexahedral (THH) PtBi/C. The Pt THH(210)/C possesses a high density of stepped atoms (dstep), exhibiting a great area activity of 1.232 mA/cm2 at 0.571 V toward ethanol oxidation, which is three times than that of commercial Pt/C (0.464 mA/cm2 at 0.594 V). Furthermore, a descriptor based on the charge density for oxygen adsorption was proposed to measure dstep on HIF-Pt catalysts.