Activity analysis of Pd-based catalysts from the performance modeling of polymer electrolyte membrane fuel cells

•Modeling-based assessment of catalytic activity is conducted for fuel cell catalysts.•Oxygen reduction and hydrogen oxidation activities are extracted.•Model validation is conducted with polarization curves of 22 Pd/Pt-based catalysts.•Effectiveness of various approaches to catalytic activity enhancement is assessed.•Degree of variation in exchange current density in each approach is quantified.