应用扫描电化学显微镜的产生/收集和反馈模式, 研究纯Mg在NaCl和Na₂SO₄溶液中腐蚀过程中的微区(点、线、面)析氢行为和活性点的演变过程. 实验结果显示, 无论在NaCl还是Na₂SO₄溶液中, 阴极极化和阳极极化均促进析氢, 与传统集气法获得的纯Mg腐蚀过程存在负差数效应一致, 但析氢速率在微区范围内波动加大, 不稳定, 且与极化程度有关. 析氢速率随NaCl浓度增加而增加, 但随Na₂SO₄浓度增加而减少. NaCl浓度增大、pH值降低、阳极极化有利于Mg表面活性点的产生.

Since electrochemical impedance spectroscopy, polarization curve and hydrogen collection were the main technologies for corrosion research of Mg and its alloy. However, those methods only provide the mean information of entire surface of corrosion electrode. In this work, H₂ evolution and active sites of pure Mg from localized sites (point, line and surface) in NaCl and Na₂SO₄ solution based on generation/collection and feedback modes of scanning electrochemical microscopy (SECM) were studied. The results indicate that both cathodic and anodic polarization are in favor of H₂ evolution in NaCl and Na₂SO₄ solution, which is well in line with the negative difference effect by the classical H₂ collection, but the SECM results show that the H₂ evolution in localized sites is not uniform and stable. The H₂ evolution rate increases with NaCl concentration increasing, which is opposite in Na₂SO₄ solution. The higher NaCl concentration, anodic polarization and lower pH value accelerate the formation of active sites on pure Mg surface.