: A : O 646. RuO 2 - TiO 2. RuO 2,. IrO 2. IrO 2 - Ta 2 O 5 ( EIS) %. Ti IrO 2 - Ta 2 O mm 15 mm 1. 5 mm, Vol. 9 No.

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1 EL ECTROCHEMISTR Y Vol 9 No 2 May 2003 : (2003) ,2, 2, 1 1, (1,, ; 2, ) :,,, : ; ; ; : O 646 : A RuO 2 - TiO 2 ( DSA ) 60, [1,2,,,, ], DSA RuO 2, IrO 2 IrO 2 [3,4 IrO 2 - Ta 2 O 5 ] (CV) ( EIS) [5,6 ] CV, EIS IrO 2 - Ta 2 O IrO 2 - Ta 2 O 5 Ir Ta 7 3, 10 % Ti IrO 2 - Ta 2 O 3 6, mm 15 mm 1 5 mm, : , : , Tel : (86-532) ; E- mail com

2 Teflon, 1 cm 2, (SCE), KCl,, 1 mol dm - 3, 30 1, 2 A cm - 2 CV EIS ACM /, 0 5 mol dm - 3 Na 2 SO 4, 20 mv s - 1, - 0 6V 1 2V V ACM EIS, 0 5 mol dm - 3 Na 2 SO 4, 30 KHz 10 mhz, 10 mv, 1 15 V 2 2 1, 480 h, 25 V, IrO 2 - Ta 2 O 5, (0h), CV 1 2 V V V Ir [7 ( ) / Ir ( ) / ], IrO 2, CV, (430 h ), CV Ir ( ) / Ir ( ),, Ta 2 O 5 1 IrO 2 - Ta 2 O 5,, Q 3 Fig 1 CV curves of IrO 2 - Ta 2 O 5 anode with dif2, Q 3 ferent electrolysis time/ h,from outside to [5 inside, 0,283,381 and 482 ]

3 2 : Q 3, 70h, Q 3, 21 mc cm mc cm - 2, Q 3, 14mC cm - 2, 430h,, Q mc cm - 2 Q 3,, IrO 2,, 2 IrO 2 - Ta 2 O 5 Fig 2 Variance of the voltammetric charge of [8,9 ], IrO 2 - Ta 2 O 5 anode with electrolysis time, IrO 2 - Ta 2 O 5 Ir, Ir IrO 2, IrO 2 RuO 2, 2 0 V 2 (vs RHE), IrO - [10,11 4 ] Q 3 [5 Ir ] Q 3 6 %, IrO 2 Ir, Ir 0 04 mg cm - 2 J Krysa [4 ] Ir, 0 06 mg cm - 2 IrO 2 - Ta 2 O 5 Ir 2 3 1) 3 IrO 2 - Ta 2 O 5, R s ( R f CPE1) ( R ct CPE2) 3, R s, R f R ct,, [12 CPE1 CPE2 ] 3,, 2) 4 IrO 2 - Ta 2 O 5 R f t, R f 0 02 cm 2 R f, Nyquist

4 R f IrO 2 TiO 2 / Ti 2 O 3 [6 ] R f, IrO 2 - Ta 2 O 5, TiO 2 / Ti 2 O 3 IrO 2 4, 350h, R f, Ir, R f 15 h, R f 3 cm 2 25 cm 2, 3 IrO 2 - Ta 2 O 5 Bode Fig 3 Bode plots of the IrO 2 - Ta 2 O 5 anode after different electrolysis time/ h : a) 0, b) 469, c) 482 3) 5 IrO 2 - Ta 2 O 5 R ct t, 70h, R ct 20 cm 2 60 cm 2, 270h, 470h 320 cm 2 15h, R ct R ct, IrO 2 IrO 2, R ct t 350 h, R f, IrO 2,

5 2 : IrO 2 - Ta 2 O 5 5 IrO 2 - Ta 2 O 5 Fig 4 Variance of the film resistance with electroly2 sis time for IrO 2 - Ta 2 O 5 anode Fig 5 Variance of the charge transfer resistance with electrolysis time for IrO 2 - Ta 2 O 5 anode, IrO 2 - Ta 2 O 5 Ir ( 30 %) Ir, R ct B V Tilak [13 ] RuO 2 - TiO 2 EIS, Ru ( < 5 %), Ru TiO 2, R f TiO cm 2 [13 ], IrO 2 - Ta 2 O 5, R f R ct, [14, TiO 2, ] TiO 2 / Ti 2 O 3 IrO 2, 4) ( CPE) (1) : Z CPE = [ Q ( j ) n ] - 1 (1),, Q, n, CPE2 n , CPE2, CPE2 Q dl [13,15 C ] dl 6 6 IrO 2 - Ta 2 O 5, IrO 2 - Ta 2 O 5 Fig 6 Variance of the double layer capacitance with elec2 trolysis time for IrO 2 - Ta 2 O 5 anode C dl

6 ,, C dl,, C dl C dl C dl IrO 2, C dl 2 Q 3 3 CV,EIS IrO 2 - Ta 2 O 5, :, Q 3 C dl, IrO 2, Ir,, R f R ct, IrO 2 TiO 2 / Ti 2 O 3,,, Q 3 C dl R f R ct Electrochemical Monitoring on t he Deactivation of a Metallic Oxide Anode XU Li- kun 3 1,2, SON G Shi-zhe 2, WAN G Ting-yong 1, CHEN Guang-zhang 1 (1 Qingdao B ranch of L uoyang S hi p M aterial Research Instit ute, S tate Key L aboratory f or M arine Corrosion and Protection, Qingdao , China, 2 School of M aterial Science and Engineering, Tianjin U niversity, Tianjin , China) Abstract : The process of accelerated life test of an IrO 2 / Ta 2 O 5 coated titanium anode was mon2 itored using cyclic voltammet ry and elect rochemical impedance spect roscopy The vatiation wit h electrolysis time of anodic voltammetric charge Q 3,the double layer capacitance C dl,the oxide film resistance R f and the charge transfer resistance R ct for oxygen evolution was measured A de2 activation mechanism was proposed based on t he observation result s Key words : Oxide,Anode,Cyclic voltammet ry, EIS Reference s : [1 ] Trasatti S Electrocatalysis :understanding the success of DSA[J ] Electrochim Acta,2000,(45) :2 377 [2 ] Nidola A Technological impact of metallic oxides as anodes,in : S Trasatti ed, Electrodes of conductive metallic oxides Part B [ M ] Amsterdam : Elsevier,1981 :627

7 2 : 183 [ 3 ] Comninellis C, Vercesi G P, Characterization of DSA-type oxygen evolving electrodes :choice of a coating[j ] J Appl Electrochem,1991,(21) :335 [4 ] Krysa J, Maixner J,Mraz R,et al Effect of coating thickness on the properties of IrO 2 - Ta 2 O 5 anodes [J ] J Appl Electrochem,1998,(28) :369 [5 ] Trasatti S Physical electrochemistry of ceramic oxides [J ] Electrochim Acta,1991,2(36) :225 [ 6 ] Lassali T A F,Boodts J F C, Bulhoes L O S Charging processes and electrocatalytic properties of IrO 2 / TiO 2 / SnO 2 oxide films investigated by in situ ac impedance measurements [J ] Electrochim Acta,1999,(44) : [ 7 ] Xu L K, Scantlebury J D Electrochemical surface characterization of IrO 2 - Ta 2 O 5 coated titanium electrodes in Na 2 SO 4 solution [J ] J Electrochem Soc,2003,(150) :B288 [ 8 ] Mraz R, Krysa J Long service life IrO 2 / Ti 2 O 5 electrodes for electroflotation [J ]J Appl Electrochem,1994, (24) :1 262 [9 ] Krysa J, Kule L, Mraz R, et al Effect of coating thickness and surface treatment of titanium on the proper2 ties of IrO 2 - Ta 2 O 5 anodes [J ]J Appl Electrochem,1996,(26) :999 [10 ] Kotz R, Neff H, Stucki S Anodic iridium oxide films [J ]J Electrochem Soc,1984,(131) 1 :72 [11 ] Pourbaix M Atlas of Electrochemical Equilibria in Aqueous Solution [ M ] Houston :NACE,1974 :373 [12 ] Kerner Z, Pajkossy T On the origin of capacitance dispersion of rough electrodes [J ] Electrochim Acta, 2000, (46) :207 [ 13 ] Tilak B V, Chen C P, Birss V I,et al Capacitive and kinetic characteristics of Ru- Ti oxide electrodes :influ2 ence of variation in the Ru content [J ] CanJ Chem,1997,(75) :1 773 [14 ] Beck F Wear mechanisms of anodes [J ] Electrochim Acta,1989,(34) 6 :811 [ 15 ] Alves V A, Silva L A, Boodts J F C Electrochemical impedance spectroscopic study on dimensionally stable anode corrosion [J ] J Appl Electrochem, 1998,(28) :899