Electrode catalyst for fuel cell and method of preparation, membrane electrode assembly (mea) including the catalyst, and fuel cell including the mea

An electrode catalyst for fuel cell, a method of preparing the electrode catalyst, a membrane electrode assembly including the electrode catalyst, and a fuel cell including the membrane electrode assembly. The electrode catalyst includes a crystalline catalyst particle incorporating a precious metal having oxygen reduction activity and a Group 13 element, where the Group 13 element is present in a unit lattice of the crystalline catalyst particle.