盐酸中原儿茶醛在钢表面的吸附及缓蚀作用

用失重法和动电位极化曲线法研究了在1.0mol/L HCl中20~50℃原儿茶醛(3,4-二羟基苯甲醛)在冷轧钢表面上的吸附及缓蚀作用.结果表明:原儿茶醛具有中等程度的缓蚀作用,为混合抑制型缓蚀剂,缓蚀率随原儿茶醛的浓度增加而增大,但随温度的增加而减小;原儿茶醛在钢表面的吸附符合Freundlich吸附模型.通过吸附理论和动力学Arrhenius公式求出了相应的吸附热力学参数(吸附自由能ΔG°,吸附热ΔH°,吸附熵ΔS°)和动力学参数表观活化能Ea,并根据这些参数详细讨论了缓蚀作用机理.

Adsorption and inhibition effect of protocatechualdehyde on steel in hydrochloric acid solution

The adsorption and inhibition effect of protocatechualdehyde (3,4-dihydroxy-benzaldehye) on cold rolled steel (CRS) in 1.0 mol/L HCl solution at 20~50℃ has been investigated by weight loss and potentiodynamic polarization methods.The results show that protocatechualdehyde acts a moderate inhibitor in 1.0 mol/L HCl, and inhibition efficiency increases with the inhibitor concentration,while decreases with the temperature.Polarization curves show that protocatechualdehyde is a mixed-type inhibitor in hydrochloric acid.The adsorption of protocatechualdehyde on CRS surface obeys the Freundlich adsorption isotherm equation.The experimental data have been treated with adsorption theory and kinetic Arrhenius equation.Three adsorption thermodynamic parameters (ad-sorption free energy ΔG°, adsorption heat ΔH°, adsorption entropyΔS°) and kinetic parameter of apparent activation energy Ea are also calculated.The inhibitive mechanism is discussed in detail according to the parameters.