Matějovský Lukáš, Staš Martin, Macák Jan
Department of Petroleum Technology and Alternative Fuels, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague, The Czech Republic.
Department of Power Engineering, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague, The Czech Republic.
ACS Omega. 2021 Jun 25;6(27):17698-17708. doi: 10.1021/acsomega.1c02320. eCollection 2021 Jul 13.
Ethanol-based E5 and E10 fuels have extensively been used as automotive fuels in gasoline engines. However, especially when contaminated, these fuels can exhibit corrosion effects on some engine construction parts such as mild steel. Thus, the study of mild steel corrosion resistance has become of the utmost importance. Electrochemical methods such as electrochemical impedance spectroscopy (EIS) and polarization characteristics measurements (Tafel scan-TS) were proven to be very valuable in studying the mild steel corrosion behavior in ethanol-gasoline blends (EGBs). However, the use of these methods was, so far, very limited for low-ethanol-content EGBs such as E5 and E10 due to their low conductivity. In this study, we present modified EIS and TS corrosion measurements based on the use of tetrabutylammonium tetrafluoroborate (TBATFB) at 500 mg/L as a supporting electrolyte. This modification led to an increase in the contaminated E5 and E10 fuels' conductivity, which allowed us to successfully perform the electrochemical corrosion tests. The corrosion current densities were determined to be 1.5 × 10 and 1.5 × 10 μA/cm for the tested E5 and E10 fuels, respectively. These modified methods present a significant extension of an electrochemical testing apparatus for steel corrosion studies in EGBs. They can allow one to obtain instantaneous information about the occurring corrosion process and, thus, estimate the materials' lifetime in corrosive environments and potentially help to prevent corrosion.
基于乙醇的 E5 和 E10 燃料已广泛用作汽油发动机的汽车燃料。然而，尤其是在受到污染时，这些燃料会对一些发动机部件（如低碳钢）产生腐蚀作用。因此，研究低碳钢的耐腐蚀性变得至关重要。电化学阻抗谱（EIS）和极化特性测量（塔菲尔扫描 - TS）等电化学方法已被证明在研究乙醇 - 汽油混合燃料（EGBs）中低碳钢的腐蚀行为方面非常有价值。然而，到目前为止，由于低乙醇含量的 EGBs（如 E5 和 E10）电导率低，这些方法的应用非常有限。在本研究中，我们提出了基于使用 500 mg/L 四丁基四氟硼酸铵（TBATFB）作为支持电解质的改进 EIS 和 TS 腐蚀测量方法。这种改进导致受污染的 E5 和 E10 燃料的电导率增加，从而使我们能够成功进行电化学腐蚀测试。对于测试的 E5 和 E10 燃料，腐蚀电流密度分别确定为 1.5×10 和 1.5×10 μA/cm²。这些改进方法显著扩展了用于 EGBs 中钢腐蚀研究的电化学测试装置。它们可以使人们获得有关正在发生的腐蚀过程的即时信息，从而估计材料在腐蚀环境中的寿命，并有可能有助于防止腐蚀。
