Ir对TiO_(2)–RuO_(2)涂层钛电极析氯性能的影响

Effect of iridium on chlorine evolution performance of titanium–ruthenium oxide electrode

针对TiO_(2)–RuO_(2)涂层钛电极析氯选择性差、寿命短的问题,采用热分解法制备了添加Ir的TiO_(2)–RuO_(2)涂层钛电极。首先对比了Ir作为中间层(IrO_(2)/TiO_(2)–RuO_(2)电极)与Ir掺杂活性层(TiO_(2)–RuO_(2)–IrO_(2)电极)两种添加形式对电极性能的影响。结果发现,与不含Ir的TiO_(2)–RuO_(2)电极相比,在0.05mol/LNaCl溶液中IrO_(2)/TiO_(2)–RuO_(2)电极与TiO_(2)–RuO_(2)–IrO_(2)电极产生游离氯的电流效率分别提升了7.4个百分点和31.4个百分点,强化寿命分别提升了14.6倍和20.0倍。进一步研究了Ru与Ir的物质的量比与涂覆层数对TiO_(2)–RuO_(2)–IrO_(2)电极析氯性能、强化寿命及活性层制备成本的影响,分析电极析氯性能的提升机制。认为IrO_(2)与RuO_(2)、TiO_(2)形成固溶体,以及Ir掺入活性层后电极表面裂缝尺寸降低与电极析氯、析氧电位差增大,是提升电极析氯选择性与寿命的关键。

Aiming at the problems of poor chlorine evolution selectivity and short service life of TiO_(2)–RuO_(2) coated titanium electrode prepared by thermal decomposition method,iridium was used as an intermediate layer to form an IrO_(2)/TiO_(2)–RuO_(2) electrode or doped into the active layer to form a TiO_(2)–RuO_(2)–IrO_(2) electrode.The properties of the electrodes were compared.The results showed that the current efficiency of producing free chlorine by IrO_(2)/TiO_(2)–RuO_(2) electrode and TiO_(2)–RuO_(2)–IrO_(2) electrode in 0.05 mol/L NaCl solution was increased by 7.4 percentage points and 31.4 percentage points respectively,and the accelerated lifetime increased by 14.6 times and 20.0 times respectively,as compared with those of the Ir-free TiO_(2)–RuO_(2) electrode.The effects of the molar ratio of Ru to Ir and the number of coating layers on the chlorine evolution performance,service life,and active layer cost of TiO_(2)–RuO_(2)–IrO_(2) electrode were studied,and the improvement mechanism of the chlorine evolution performance of the electrode was analyzed.It is concluded that the formation of solid solution of RuO_(2),TiO_(2),and IrO_(2),the reduction of the size of cracks on electrode surface,and the increase of the difference between chlorine evolution potential and oxygen evolution potential of the electrode after doping of Ir into the active layer are the keys to improvement of the chlorine evolution reaction selectivity and service life of the electrode.