Electrode catalyst for fuel cell, method of preparing the same, and membrane electrode assembly and fuel cell including the electrode catalyst

An electrode catalyst for a fuel cell, the electrode catalyst including a first catalyst A that exhibits hydrophilicity, the first catalyst including pores, wherein at least 50 volume percent of the pores have an average diameter of about 100 nanometers or less; a method of preparing the electrode catalyst; and a membrane electrode assembly (MEA) and a fuel cell that include the electrolyte catalyst. The electrode catalyst for a fuel cell rapidly controls the migration of phosphoric acid at an initial stage of operation of an MEA, thereby securing a path for the migration of a conductor and a path for the diffusion of a fuel, and thus, an activation time of the MEA is shortened.