*2.4. Electrochemical Measurement*

A WBE scanner (CST520, Wuhan Corrtest Instruments Corp. Ltd., Wuhan, China) was used, and the acquisition time interval for each data point was 3 s. Conventional electrochemical experiments were carried out using a Parstat 4000+ electrochemical workstation with a three-electrode cell, a saturated calomel reference electrode (SCE), a platinum plate larger than the working electrode area as the counter electrode, and L360 steel as the working electrode. The EIS measurement frequency range spanned from 10 mHz to 100 kHz, the scan rate of the potentiodynamic polarization curve was 0.3 mV/s, and the potential was between −500 mV(vs. OCP) and +500 mV(vs. OCP). Zview software was used to simulate the impedance data using an equivalent circuit. All the tests were carried out at 60 ◦C.
