<p>This study systematically investigates the influence of atomic doping (Ru, Pd, Os, Ir, Au, Rh) on thermodynamic stability, elastic modulus, and electronic structure of Pt-based alloys using first-principles methods. Calculations of cohesive energy confirm the stability of the resulting solid solutions. Doping with Au atoms enhances the bulk modulus, while the doping of other atoms lowers it. Doping with Ru, Os, Ir, Au, and Rh augments the shear modulus, Young’s modulus, and hardness, whereas Pd doping decreases these properties. The doping of all alloy atoms raises the dislocation energy. Calculations of Poisson’s ratio, B/G ratio, and Cauchy pressure reveal that the doping of all atoms weakens the plasticity of the solid solution. The total density of states of the Pt solid solution primarily originates from the contributions of Pt and X atoms’ d orbitals, and the doping of alloy atoms predominantly affects the stability of the formed Pt-X covalent bonds.</p> Graphical abstract <p>This study utilizes first-principles calculations to investigate how atomic doping (X = Ru, Pd, Os, Ir, Au, Rh) impacts the structural stability, mechanical properties, and electronic structure of Pt-based solid solutions. Doping induces lattice distortion and alters covalent bonding characteristics, significantly influencing hardness, modulus, dislocation energy, and melting point. Notably, Os doping provides the greatest enhancement in strength-related properties, while Pd weakens mechanical performance.</p> <p>Figure: The structure of the Pt and Pt-X solid solution structure : (a) Pt solid solution structure (b) Pt-X solid solution structure</p> <p></p>