Research Of Titanium-based Anode Materials For Electrocatalytic Production Of Sodium Hypochlorite

Electrolytic chlorine reactions are widely used in many fields such as chlor-alkali chemicals,medical disinfection,offshore equipment corrosion protection,and wastewater treatment.The anode materials used in electrolytic devices are often referred to as dimensionally stable anodes（DSA）and are mainly available as industrial ruthenium-titanium electrodes and commercial ruthenium-iridium electrodes.These anode materials often need to work stably for decades at high current densities and maintain high current efficiency,while existing electrodes often suffer from insufficient stability,low selectivity,and high manufacturing costs.To address these problems this paper modulates the electronic structure of the catalytic layer on the electrode surface by doping the catalytic layer with inert metal elements,forming solid solutions,and modifying the substrate nanostructure to increase the number of active sites while improving the electrode stability.The Ti/RuZrSbO_x-TD electrode prepared by this method has small and dense surface cracks and a flatter surface compared with the Ti/RuZrSbO_x-SG electrode prepared by the sol-gel method,and the elements are evenly distributed and the ratio in the precursor solution does not change much.It can form a homogeneous and stable solid solution.The Ti/RuZrSbO_x-TD electrode has a lower onset potential of 1.77 V vs.RHE and higher current efficiency（87.43%）compared with the commercial ruthenium-iridium electrode,while its stability is 50%higher than that of the commercial ruthenium-iridium electrode.The Ti/RuSnNbO_x,Ti/RuIrSnSbO_x and RuIrSnSbO_x@TNS DSA electrode materials were then synthesized by applying a modified pyrolysis method.The Ti/RuIrSnSbO_xelectrode has both high catalytic activity and high stability,and the sample has the highest catalytic activity when the Ir addition ratio is 7%,corresponding to a starting potential of 1.72 V vs.RHE at 10 m A/cm² and 1.78V vs.RHE at 100 m A/cm²,with a current efficiency of 91.4%in 0.5 M H₂SO₄,at 2A/cm²,the stability of accelerated life test was maintained for 91 hours.The catalytic activity and stability of the electrode were further improved by the nanomodification of the titanium substrate with a current efficiency of 92.3%and a failure time of 109 h in sulfuric acid.