Surface catalysis based on ruthenium dioxide for effective activation of aluminium sacrificial anodes

Abstract Several studies have been focusing on alloying and structural modification of aluminium alloy sacrificial anodes using different activators including intermetallic compounds. With a novel approach, the present work explore and evaluate the feasibility of effective aluminium activation by RuO 2 in 95 + 5 Al–Zn alloy substrates. The electrodes prepared in the present work, by making RuO 2 film on the substrate, were found to possess good surface interaction, low surface resistivity and facilitate interlayer diffusion of aluminium ions. The electrodes showed excellent galvanic performance under different experimental conditions in 3% NaCl electrolyte. The RuO 2 layer was found to persist on the electrode surface even after the electrode size was reduced to one-third of its original size due to long period of galvanic exposure, evidencing its mobile character. The electrodes are economically efficient, convenient to prepare as other conventional hanging electrodes, tolerable to very aggressive media and highly efficient even under high current load.