The interplay between surface area and sulfur doping of carbon support on Pt NPs nucleation and growth: A synergistic enhancement of catalytic activity for oxygen reduction

Metal-carbon interaction plays a fundamental role in tuning the electrocatalytic behavior of metal nanoparticles (NP). The aim of this study is to emphasize the effective synergy between sulfur doping and the porous structure of the carbon support on the Pt NPs morphology and dimension. Thiophenic-like defects exert a metal-support interaction that affects Pt NPs nucleation and growth and their catalytic activity versus the oxygen reduction reaction (ORR), which makes them promising candidates for the cathode side of PEMFC. Pt NPs defectivity, size, and size dispersion were asserted by using synchrotron wide-angle X-ray total scattering and advanced data analysis. The analyses confirm a mutual correlation between the carbon surface area and the density of sulfur groups with the Pt-specific surface area and with their electrocatalytic properties. The catalytic activity for ORR reaches its peak when a balance is struck between the mesoporosity and the sulfur functionalization of the carbon support.