Kinetic model of induced codeposition of Ni-Mo alloys

The kinetic model of induced codeposition of nickel‐molybdenum alloys from ammonium citrate solution was studied on rotating disk electrodes to predict the behavior of the electrode‐position. The molybdate (MoO₄^2?) could be firstly electro‐chemically reduced to MoO₂, and subsequently undergoes a chemical reduction with atomic hydrogen previously adsorbed on the inducing metal nickel to form molybdenum in alloys. The kinetic equations were derived, and the kinetic parameters were obtained from a comparison of experimental results and the kinetic equations. The electrochemical rate constants for discharge of nickel, molybdenum and water could been expressed as k₁,(E) = 1.23 × 10^?9 C_Nexp( ‐ 0.198 FE/RT) mol/(dm² · s), k₂ (E) = 3.28 × 10^?10 C_Moexp ( ‐ 0.208FE/ RT) mol/(dm² · s) and k₃(E) = 1.27 × 10^?6 exp ( ‐0.062FE/ RT) mol/(dm² · s), where C_N and C_Mo, are the concentrations of the nickel ion and molybdate, respectively, and E is the applied potential vs. saturated calomel electrode (SCE). The codeposition process could be well simulated by this model.