The effect of ‘hot’ electrons on the heterogeneous adiabatic charge transfer reactions

The spin-less version of the Anderson Hamiltonian is extended to describe the adiabatic electron transfer reactions at a metal electrode involving ‘hot’ electrons which can be reached by the subpicosecond laser pump. The latter presumes high temperatures of the electron gas in the metal substrate, significantly exceeding the temperature of solvent bath. Some analytical formulas are derived and employed to construct the adiabatic free energy surfaces along the solvent coordinate as a function of the electrode overpotential. The model calculations show a noticeable decrease of the reaction barrier resulted from the effect of ‘hot’ electrons. A difference in the kinetics of adiabatic and diabatic electron transfer induced by ‘hot’ electrons was found to be noticeable. The dependencies of the symmetry coefficient vs. the overpotential are discussed, as well as the contribution from vibrationally excited states.