Adsorption and Inhibition Effect of Vanillin on Steel in H₂SO₄ Solution

The adsorption and inhibition effect of vanillin (4-hydroxy-3-methoxy-benzaldehyde) on cold rolled steel (CRS) in 1.0 mol/L H2SO4 solution at 10~40 ℃ has been investigated by weight loss method.The inhibition efficiency of vanillin increased with the increasing of inhibitor concentration,and decreased with the temperature increment.The adsorption of vanillin on CRS surface obeyed the Temkin adsorption isotherm equation.The experimental data had been treated with adsorption theory and kinetic Arrhenius equation.Three adsorption thermodynamic parameters (adsorption free energy ΔG0,adsorption heat ΔH0,adsorption entropy ΔS0) and two kinetic parameters (apparent activation energy Ea,pre-exponential factor A) were also calculated.The inhibitive mechanism was discussed in detail according to the parameters.