【作者】 王敏；

【导师】 薛丽莉；

【作者基本信息】 哈尔滨工程大学 ， 化学工程与技术， 2025， 硕士

【摘要】 金属氧化物阳极是涉海装备电化学阴极保护系统中的关键部件,其存在低温环境下电催化活性降低和服役寿命缩短的问题。利用的石墨烯（GO）、碳纳米管（CNTs）的高电子迁移率解决该问题是当前研究的热点。本文利用纳米RuO₂粒子锚合GO-CNTs-诱导RuO₂-IrO₂-SnO₂原位生成两步法制备RuO₂/GO-CNTs增强RuO₂-IrO₂-SnO₂复合阳极,解决了GO-CNTs与阳极金属氧化物之间结合不良的问题。采用扫描电镜、X射线光电子能谱等方法对复合阳极形貌和物相进行分析,利用极化曲线、强化电解寿命等方法研究了RuO₂负载量和环境温度对复合阳极性能的影响规律,并初步探讨了复合阳极的失效机制。制备了RuO₂负载量分别为45 wt%、55 wt%、65 wt%的RuO₂/GO-CNTs增强RuO₂-IrO₂-SnO₂阳极,并对阳极微观结构和性能进行了系统研究。研究结果显示,当RuO₂负载量为55 wt%时,阳极涂层表面裂纹变微小且不连续,阳极的比表面积增加;与未经RuO₂负载修饰的阳极对比,电化学粗糙度由15.09%增大到76.22%,电化学表面积显著增大。伏安电量由4.64 m C·cm^-2增大到18.68 m C·cm^-2,活性位点数量大幅增加,电荷转移电阻由18.06Ω·cm^-2降至4.04Ω·cm^-2,析氧析氯电位差由0.25 V增大到0.36 V,电催化活性显著提高;结晶度的提高,电化学孔隙率由94.70%降低至85.26%,强化电解寿命由300 h延长至765 h。研究结果表明,RuO₂负载量为55 wt%的复合阳极的电催化活性和稳定性最优。研究了环境温度对复合阳极性能的影响规律。不同复合阳极的电催化性能均随着温度的降低而下降,但RuO₂负载量为55 wt%时复合阳极在各温度条件下均展现出更高的电流密度和活性位点数量,具有更高的电催化活性;并且其具有较高的结晶度,在各种温度下均具有优异的电化学稳定性,在0℃下的强化电解寿命仍可达470 h,阳极寿命大幅提升。复合阳极的失效为活性溶解-结构劣化-界面失效的多重作用机制。在强化电解过程中,活性组分的溶解触发涂层孔隙率上升,加速裂纹扩展,裂纹的形成进一步加剧钛基体氧化,生成了不导电的TiO₂钝化层,导致阳极阻抗由11.78Ω·cm^-2增大至59.11Ω·cm^-2,最终导致阳极涂层失效。更多还原

【Abstract】 The metal oxide anode is a key component in the electrochemical cathodic protection system of offshore equipment,which has the problems of reduced electrocatalytic activity and shortened service life at low temperatures.The high electron mobility of graphene（GO）and carbon nanotubes（CNTs）is the focus of current research.In this paper,a RuO₂/GO-CNTs reinforced RuO₂-IrO₂-SnO₂ composite anode was prepared by a two-step method in which nano-RuO₂ particles anchored GO-CNTs induced RuO₂-IrO₂-SnO₂ in situ.It solves the problem of poor combination between GO-CNTs and anode metal oxides.The morphology and phase of the composite anode were analyzed by scanning electron microscope and X-ray photoelectron spectroscopy.The effects of RuO₂ loading and ambient temperature on the performance of the composite anode were studied by polarization curve and enhanced electrolytic life.And the failure mechanism of the composite anode was preliminarily discussed.The RuO₂/GO-CNTs reinforced RuO₂-IrO₂-SnO₂ anode with 45 wt%,55 wt%and 65 wt%of RuO₂ was prepared.And the microstructure and properties of the anode were systematically studied.The results show that when the RuO₂ loading is 55 wt%,the surface cracks of the anode coating become small and discontinuous,and the specific surface area of the anode increases.Compared with the anode without RuO₂ loading modification,the electrochemical roughness increased from 15.09%to 76.22%,and the electrochemical surface area increased significantly.The voltammetric capacity increased from 4.64 m C·cm^-2 to 18.68 m C·cm^-2,and the number of active sites increased greatly.The charge transfer resistance decreased from 18.06Ω·cm^-2 to4.04Ω·cm^-2.The potential difference of oxygen and chlorine evolution increased from 0.25 V to 0.36 V,and the electrocatalytic activity was significantly improved.With the increase of crystallinity,the electrochemical porosity decreased from 94.70%to 85.26%,and the life of enhanced electrolysis increased from 300 h to 765 h.The results show that the composite anode with 55 wt%RuO₂ loading has the best electrocatalytic activity and stability.The influence of ambient temperature on the performance of the composite anode was studied.The electrocatalytic performance of different composite anodes decreased with the decrease in temperature.However,when the RuO₂ loading is 55 wt%,the composite anode exhibits higher current density and the number of active sites at all temperatures,and has higher electrocatalytic activity.Moreover,it has high crystallinity and excellent electrochemical stability at various temperatures,and its service life can still reach 470 h at 0℃,which greatly improves the anode life.The failure mechanism of the composite anode is active dissolution,structural degradation,and interface failure.In the process of enhanced electrolysis,the dissolution of active components triggers the increase of coating porosity and accelerates crack propagation.The formation of cracks further aggravated the oxidation of the titanium matrix,resulting in the formation of a non-conductive TiO₂ passivation layer,which led to the increase of anode impedance from 11.78Ω·cm^-2 to 59.11Ω·cm^-2.And finally led to the failure of the anode coating.更多还原