Modification of Pt catalysts to achieve satisfactory activities for commercialization of proton exchange membrane fuel cells has attracted widespread attention in recent years. In this study, a simple one-pot wet-chemical approach for incorporation of phosphorus (P) into Pt to form a supported Pt₅P₂ alloy phase was developed to enhance the catalytic properties of Pt catalysts toward the methanol oxidation reaction (MOR), including both the activity and durability. The simultaneous use of NaH₂PO₂ and Na₂HPO₄ is the most crucial for the formation of the Pt₅P₂ phase, and the introduction of P results in a smaller size, better dispersion, and the electronic structure change of Pt. The Pt₅P₂/C catalyst achieves a factor of 11.0 and 9.1 enhancement in mass activity (3.603 A mg_Pt⁻¹) and specific activity (63.43 A m⁻²)for the methanol oxidation reaction (MOR) relative to Pt/C, respectively. Moreover, 5000 cycles of the accelerated durability test demonstrated that excellent durability could be obtained for Pt₅P₂/C, with a drop of 11.8% in mass activity, much smaller than both Pt/C and Pt/C-JM. To the best of our knowledge, this is the first report to identify MOR performance on Pt₅P₂. Given the highly improved catalytic performance, one can anticipate that nanocatalysts composed of Pt and P atoms would shed new light on fuel cells and offer a novel research idea for promoting activity and durability of Pt electrocatalysts.