Corrosion inhibition in acidic environments: key interfacial insights with photoelectron spectroscopy.
Corrosion inhibition in acidic environments: key interfacial insights with photoelectron spectroscopy.
复制标题
酸性环境中的腐蚀抑制：光电子能谱的关键界面见解。
DOI：
10.1039/d1fd00106j
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发表时间：
2022
影响因子：
3.4
通讯作者：
Kousar K
中科院分区：
文献类型：
--
作者：
Kousar K
在许多工程场景中，表面活性有机物质被添加到酸性溶液中以抑制金属部件的腐蚀。如果选择合适的缓蚀剂，这种缓蚀剂是非常有效的，即使在高度侵蚀性的环境中也能防止显著的降解。然而，在缓蚀剂功能的基础知识方面仍存在相当大的差距，严重制约了合理开发。在这里，我们展示了X射线光电子能谱（XPS）的能力，从头算模型的支持下，揭示抑制基板的关键细节。注意力集中在碳钢的腐蚀抑制，通过添加一个示例性的咪唑啉为基础的缓蚀剂（OMID）的HCl和H2SO4的水溶液。最值得注意的是，它表明，界面化学随身份的酸。高分辨率的Fe 2p，O 1s，N 1s，和Cl 2p XPS光谱，获得良好的抑制碳钢在1 M HCl中，表明有两个不同的单质子化OMID物种直接绑定到金属碳钢基板。与此形成鲜明对比的是，在0.01 M H2SO4中，OMID吸附到超薄表面膜上，主要由硫酸铁（Fe2（SO4）3）样相组成。这种洞察力对于开发缓蚀剂功能的机械描述以及基于知识的下一代缓蚀剂识别的努力至关重要。
In many engineering scenarios, surface-active organic species are added to acidic solutions to inhibit the corrosion of metallic components. Given suitable selection, such corrosion inhibitors are highly effective, preventing significant degradation even in highly aggressive environments. Nevertheless, there are still considerable gaps in fundamental knowledge of corrosion inhibitor functionality, severely restricting rational development. Here, we demonstrate the capability of X-ray photoelectron spectroscopy (XPS), supported by ab initio modelling, for revealing key details of inhibited substrates. Attention is focussed on the corrosion inhibition of carbon steel through the addition of an exemplar imidazoline-based corrosion inhibitor (OMID) to aqueous solutions of both HCl and H2SO4. Most notably, it is demonstrated that interfacial chemistry varies with the identity of the acid. High resolution Fe 2p, O 1s, N 1s, and Cl 2p XPS spectra, acquired from well-inhibited carbon steel in 1 M HCl, show that there are two different singly protonated OMID species bound directly to the metallic carbon steel substrate. In sharp contrast, in 0.01 M H2SO4, OMID adsorbs onto an ultra-thin surface film, composed primarily of a ferric sulfate (Fe2(SO4)3)-like phase. Such insight is essential to efforts to develop a mechanistic description of corrosion inhibitor functionality, as well as knowledge-based identification of next generation corrosion inhibitors.