In this work we report results related to hydrogen evolution and absorption, on AISI 1045 steel and AISI 1045 steel modified by Sn electrodeposition, in 1 M NaOH. The simulation of experimental impedance, steady-state j/E data and electrochemical permeation data in terms of the Volmer–Heyrovsky mechanism coupled to H absorption and diffusion, allowed the estimation of kinetic and transport parameters leading to an appropriate interpretation of diminished H absorption on Sn modified samples.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas