Small-angle X-ray scattering of carbon-supported Pt nanoparticles for fuel cell

Small-angle X-ray scattering is applied to investigate the structure of Pt nanoparticles for fuel cells with high Pt mass loading at various hot pressures. The two-dimension-like and monolayer aggregates with fractal structure formed from primary (or elementary) Pt particles are found. The SAXS analysis of size, shape, specific surface and structure of both the aggregates and the primary Pt particles is reported here, using model-independent and model-fitting methods. The analysis yields self-consistent results. This quantitative characterization is used to evaluate the role of Pt catalysts regarding different process parameters, and provides useful information for improving fuel cell performance.