Increasing the Service Lifetime of Coated Titanium Anodes

Abstract

Mixed metal oxide coated titanium anodes have been applied widely to cathodic protection as impressed current anodes in the oil/gas industry and for chlorine production in chlor-alkali industry. The anodic stability and service life are the main concerns in these applications. It has been known that oxide anodes have a very limited service life under operating conditions because of the severe corrosion of active component in the oxide mixture such as RuO 2 , leading to final deactivation of the anode.To increase the effective life of anodes, this study considered alternative anode materials and concluded that the anode life is improved by doping the anode coating with IrO 2 . Therefore, corrosion behaviour of a RuO 2 -IrO 2 -TiO 2 /Ti oxide anode was investigated during an accelerated life test (ALT) in NaCl solution by use of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and SEM/EDS. The service lifetime of IrO 2 doped oxide coating is compared with RuO 2 /Ti and RuO 2 -TiO 2 /Ti anodes and a systematic evaluation is presented.The life test indicated that the improved oxide anode has a long lifetime and appropriate activity. It was concluded that RuO 2 -IrO 2 -TiO 2 /Ti anodes last up to ten times longer than Ir-free anodes. An impedance model is then developed for this corrosion system and the model simulation compared to the experimental data. The model is shown to be in reasonable agreement with the experimental data. A comprehensive deactivation mechanism of titanium anodes has been proposed by the growth of an insulating TiO 2 layer at coating-substrate interface.The results presented in this paper are very promising and reveal that RuO 2 -IrO 2 -TiO 2 /Ti anode has a good potential to be used as mixed metal oxide anode in oil/gas and petrochemical industries.

Ruthenium oxide based microelectrode arrays for in vitro and in vivo neural recording and stimulation

“…This suggests that the addition of ruthenium oxide may prevent degradation and that RuOx electrode coatings may be suitable for chronic neural interfaces (Ullah and Omanovic, 2015). Additionally, prior studies of the electrochemical performance of ruthenium oxide electrodes have reported high charge storage capacities, high electrical conductivity, and a large electrochemically active surface areas [22,25,[33][34][35][36][37]. While these and our studies report promising results, future studies are necessary to determine the chronic reliability of implantable RuOx electrodes for recording and stimulation applications.…”