Korean Chemical Engineering Research

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(1)Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005, pp. 118-124. ?÷W¯§ C C SPE O,6/£ g» Z PEMFC§£ ô. ` o §|* <ÐS** §`û*** ¿< »LÇ. †. õ§¬H/ dHàHê ÖQ ¬éC Uô 134 *(?)Á dHõC 431-080 , 8Q 8C Dª 183 **SKC(?) OJõC 440-301 , ¤òQ ß8C _É1 911 ***KdKdH(?) OJõC 305-345 ¬MQ K C U 6 (2003¸ 10ö 14³ [¤, 2004¸ 10ö 19³ >) 120-749. Preparations of SPE Electrocatalysts Modified with Polypyrrole and Its Application for PEMFC Jung-Hoon Kim, Seung-Duck Oh, Han-Sung Kim*, Jong-Ho Park**, Jung-Woo Han***, Kang Taek Lee and Yung-Il Joe† Department of Chemical Engineering, Yonsei University, 134, Sinchon-dong, Seodaemun-gu, Seoul 120-749, Korea *Hyosung Corporation R&D Center for Chemical Technology, 183, Hoge-dong, Dongan-gu, Anyang, Kyonggi-do 431-080, Korea **SKC Central R&D Center, 911, Chongja-1-dong, Changan-gu Suwon, Kyonggi, 440-301, Korea ***Hanwha Chemical Research & Development Center, 6, Shinsung-dong, Yusung-gu, Daejeon 305-345, Korea (Received 14 October 2003; accepted 19 October 2004). ß È. á õCÑ2 ·-)»³ í0ê Nafion LÑ )[Jk³ ñkõ (G2 örs fQGÊ PEMFC³ Äs ]G. íQf³ FeCl Ú Na S O s ÄGñ )»s Nafion LÑ OYG. fÆê PPy/Nafion ÞY L «5 MQ W¤Ss +_K ê, Na S O s ÄGñ fÆê ÞY Lo )» OYQÑ« ÍO¤´ «5 MQ W¤So ÝGÊ, FeCl Î W¤So ÝG(O «5 M2 K(æÉ. ·-)»³ í0ê Nafion LÑ ñkõ dHJ hòrÑ g WzK ê, ·-)» MÉ M 7 Ñ g ( Í ös < ¤ ÀÉ. K, Pt/PPy/Nafion MñkQ e Mk³ C ê MEAõ . õ0M( D Íõ }K ê, 0.3 V M.Ñ 569 mA/cm MÍÊ às ä2 õ0M( Ds »s ¤ ÀÉ. 3. 2 2. 8. 2 2. 8. 3. 2. Abstract − In this study, a novel deposition method of Pt catalysts onto Nafion membranes modified with polypyrrole (PPy) has been proposed for PEMFC application. The PPy/Nafion composite membranes were fabricated by chemical polymerization of pyrrole using FeCl3 and Na2S2O8 as initiator. The proton conductivity and water uptake of the chemically prepared PPy/Nafion composites were investigated. The ionic conductivity and water uptake of PPy/Nafion composite membrane prepared with Na2S2O8 were decreased with polymerization time of pyrrole. In the case of FeCl3, the ionic conductivity was almost retained and the water uptake was decreased with polymerization time of pyrrole. When the Pt particle was deposited on PPy/Nafion composites membrane by chemical reduction of H2PtCl6, the Pt loading on Nafion membrane was enhanced by polypyrrole due to electronic conduction property. The performance evaluation with membrane electrode assembly composed of Pt/PPy/Nafion composite and diffusion electrode was carried out using a single cell. As a result of fuel cell test, current density of 569 mA/cm2 at 0.3 V has been obtained for MEA contained with Pt/PPy/Nafion composite. This study shows that direct deposition of Pt catalysts on Nafion impregnated polypyrrole is a promising method to prepare thin catalyst layer for the PEMFC. Key words: PEMFC, Polypyrrole, Nafion, PPy/Nafion, Pt/PPy/Nafion, Electroless Reduction. † To. whom correspondence should be addressed. E-mail: [email protected] 118.

(2) ·-)»³ í0ê SPE Mñk. 119. 6÷ Nafion ,

(3) Ñ ·-)»« OYæ´ Às Î ÄU hòÑ @ æ2 MÉÍ M s 2 ·-)»³ «« Ä «Gj æ´ Nafion LÑ ñkÍ j @ î ¤ Às a«. «ao ñkõ Nafion ,

(4) .Ñ )[ ( ÿ2 *³Ò ö rk³ (

(5) s j fÓ ¤ ÀÊ, sputterings «ÄK ñk ( ÁêÍ ,¬î ¤ Às a«. á õgÑ2 Nafion L ,

(6) Ñ ñkõ )[ ( ÿ, .g *³Ò örs f8G. M Ê~É¯ ·-)»s Nafion LÑ OY á ÄUs dHJk³ hòE L ,

(7) Ñ ñk@s G. hòÑ g ê _hôY(platinum nucleation sites)o ½É ¿,Í ÍWÑ ¶ hòäo åMg ä« ( J«j æ, dHJ örk³ hò fQ ÄU hò äÑ @ æ2 MÉ2 ÄUê Nafion k³ «O ¤ Çs a«[11]. ¶ Nafion LÑ ê · -)»o Nafion SO õ 6T³ G2 MÉ M s 2 í0 ³ ÊÄGñ ÄU hòäs ñ,O ak³ ê. ¶ á õgÑ2 ·-)»s Nafion zÑ OYE Pt/Nafion ÞY M fÆ W QÝ Ú D s 0g PEMFC³ Äs IJk³ G. − 3. Fig. 1. Mechanism for the polymerization of pyrrole.. 1.. C «. M Ê~É OÑ ·-)»o dHJ Ú ùJ 8_ « ¿Ê M « Î¤G dHJ Y « Ä«K í0«. Mg0 ÄUÑ )» MgOY ,g2 Fig. 1Ñ ÷ àQ ç« ¶ «5

(8) 2 f2 ¶ «5

(9) Q äGñ & í ¤òÉõ ´ {k³ «

(10) Í ê. öÇ

(11) Q Ê~ É

(12) oligomer2 )»

(13) Ý dä« j ³´÷ ¶ «5

(14) Q ª äGñ )» õGÍ ßGj ê. «) Ê~É õG MGÑ ¬G2 MG Ý s .g Mg0 {«5 eÑ g ?« ,}ê. Y ê ·-)» { «5 o Ý0 )» .¢ 0.25-0.33í³ <s À. Y ê · -)» M Ú «5 Gh U o ?æ2 {«5 ÜÍQ ¿,Ñ g _æ, Nafion ÄUê ço M¬ {«5« ·-) »Ñ ? ê

(15) @ ê ·-)»o «5 GhU s ÷. «ao «5 GhL «5 M ê K÷Í(³ ·-)»Ñ ?ê M¬ 6TÍ d hòê_ 8 ·-)»Ñ Ê_dæ´ ? %? äÑ ñG( :k³ ?ê M¬ {«5« « 5 Ê_MÉ òOs ¢G2 ak³ <s À. ¶ ·-) »Ñ Nafion ÄUê ço M¬Ê~É {«5s ?G2 íÄê K. Gj Nafion LÑ ·-)»s j OYO ¤ Às a«[1-6]. Nafiion LÑ ê ço Ç ñkõ )[ zJÿ2 ör Ñ2 ?³ sputtering«÷ Takenaka-Torikair(T-Tr)« «ÄæÊ À . Sputtering Î2 à W£ ßjÍ 1®G, o Ñw( ö Ñ K L « Îsê. K, T-Tr Î Äæ2 ÄU« ¬Jk³ QÊ, Nafion Lê Ç ñk í-J [ô« uGñ j t( ª

(16) I]« (2 Y« À. ¶ Íer Ùs «ÄGñ ñkQ Nafion L [ñts «M÷, ñ¶ K Ùs «ÄGñ L Mr,õ Íÿ2 õg Í ,}æÉk÷ Ä

(17) s ¿j Ýÿ(2 \G[7-10].. 2.. /ð£ Z tà. 2-1. PPy/Nafion (´ÿ g» Z |K á ×Ñ ÄK Mg0Lk³2 Dupont Nafion 117s. ÄG. M Ê~É³ pyrrole monomer(MW=67.09, Acros)õ _f Ç« ÄGÊ, df³2 ferric chloride(FeCl , Sigma) Q sodium persulfate(Na S O , Sigma)õ ÄG. Nafion L Ms-2 LÑ 4À2 K,¨íê ¨í fMõ .Gñ 1:1 WS HNO ¤ÄUÑ 1Ñ 8 ¨¯ á Í¤Ñ 1 Ñ 8 ¨. PPy/Nafion ÞY Lo Fig. 2Q ço ä, K \ Ñ 0.2 mol/L pyrroles ñ \ Ñ íf³ 0.1 mol/L FeCl Ú 0.1 mol/L Na S O õ ½Gñ ÑÑ ¶ ·-)»s OYG . ·-)»« OYê

(18) Jo 2 2 cm «ÉÊ, fÆê PPy/Nafion ÞY L =õ H k³ ¡dE?, .Gñ 0.5 mol/L H SO Ñ 2Ñ « Í &É. Polyyrrole OYs e¯G, .Gñ fÆê PPy/Nafion Ls optical microscopyQ AFM(Digital Instrument NanoScope III scanning probe microscope)s «ÄGñ îûG. ·-)»« OYê Nafion «5 GhL «5 M Ú W¤S ¡dõ pyrrole OY 3. 2 2. 8. 3. 3. 2 2. 8. 2. +. 2. 4. Fig. 2. Schematic of reaction cell for PPy/Nafion composite membrane. Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005.

(19) 6_åö19 ö6K öáÜDöK_Îö«ã>öÆ³. 120. ÑÑ ¶ <4ÝI. «5 M2 fÊê PPy/Nafion ÞY Ls 0.5 mol/L H SO ÄUÑ 2Ñ « Í* á GÍ ») A rk³ +_G. MgUk³2 0.5 mol/L H SO s ((Mg 0³ ÄGk, »)A +_o IM6(Zahner Co.)õ ÄGñ ?²¤ ò 200 mHz-100 kHz, GÍ D ±10 mVõ ¯ÍGñ ×G. ¯ÍM.2 í¡³ MF(open circuit voltage)Ñ ») Aõ +_Gñ Þ

(20) ê O÷2 ÄUI]s PPy/Nafion ÞY L I]àk³ _G. ÞY L «5 M2 { Ñ g ªG. 2. 4. 2. 1 l Ionic conductivity(σ)= ---- ⋅ ---R A. 4. (1). ñ, R=membrane resistance (Ω)-bulk resistance (Ω) ñ, l=membrane thickness (cm) ñ, A=membrane area (cm ) Nafion W¤S ¡d2 )» OY ÑÑ ¶ +_G. Î PPy/Nafion ÞY Ls ð¨¤Ñ 24Ñ Í&ÉÊ, PPy/ Nafion QÆåj2 60 C ,à1Ñ 12Ñ QÆ á +_G . W¤So { Ñ Gñ ªG. 2. o. wwet – wdry - ×100 Uptake content(%)= -----------------------wdry. s Q³ _G. K, ÄK

(21) ê roughness factorQ W Í l W,

(22) Jk³ {ê ço k³ ,ê. Roughness factor Surface Area= ----------------------------------------Pt loading. (4). !OO £ ·| Z |ðl` ´·- Ñ !4M, íA, õ´ Ú MÍ4Mõ ó³ jGñ .M(õ g G. íAo , Kê crossoverõ ö(Wê Ñ Ê~É L s ö(G, .g. ÄG. õ ó ä,Q M [ñ

(23) Js ¬dGÊ ä ,õ ÁêJk³ «ÄG, .Gñ parallel-seriess ÄGk , ä

(24) Jo 4 cm « æ´ G. MÍ 4M2 M,¾õ zôGñ M( z 5ÆQê MÍ4M òOs Ñ O ¤ À. Carbon black(Vulcan-XC) 0.1 g, PTFE 0.05 g, IPA 2 g, HYUs PTFE(60 W%)³ è¤ s-K carbon cloth .Ñ rollingGñ , e@s Gñ Pt/PPy/Nafion Mê 120 C, 3 Meric tonÑ 3~Ñ hot pressingGñ MEAõ fÆG. ä,2 mass folw controllerÑ K

(25) « ÆQê á, ÍS,õ 0êGñ ÍS =³ . M(Ñ ½æ, ¤Q M,dHJ äÑ Gñ è@ê MÍ2 DC Electronic Load(Model-6060B, Hewlett Packard Co.)Ñ 2-3.. 2. o. (2). ñ, w o QÆ:ñ åj«Ê w o ò :ñ åj«. 2-2. Pt/PPy/Nafion (´ÿ O,£ g» Z |K )» OYÑÑ ¶ fÆê PPy/Nafion ÞY Ls Fig. 2Q K K ä, «Ñ ÙÎÊ K\ Ñ2 0.5 mol/L sodium borohydride(NaBH , Samchun)õ hòf³ ÄGÊ, ñ \ Ñ 2 5 mmol/L platinic chloride(H PtCl , Sigma)s z)õ ¡dE s hòZ. ä Ño 40~ 8 ³_Gj K(GÊ fÆ ê Pt/PPy/Nafion ÞY Mo 0.5 mol/L H SO ÄUÑ 2Ñ 8 Í &É. ( á UV-vis spectrophotometer(UV-2401PC, SHIMADZU)õ «ÄGñ ÄU {«5 Âä s gG Ê, PPy/Nafion ,

(26) Ñ @ æ( :Ê zMê åjõ +_ Gñ ÄK k³z (

(27) s ªG. õ0M( DÑ ÄK MEAQ2 ?Jk³ Pt/PPy/Nafion Þ Y M l

(28) J, ,

(29) J Ùs <4Ý, .Gñ cyclic voltammetryõ }G. MÍ-MF2 potentiostat(Wenking PGS 81)³ −0.3 V-1.2 V p.Ñ 40 mV/s³ ? Gñ +_G . Æ Mo Ag/AgCl(TOA Electronics Ltd.)s ¬k³ ¶s. ÄGñ 3 M cellÑ +_G. ((Mg0³2 0.5 mol/L H SO ÄUs ÄG. Ñ ¬K ¤ ô« ³¬ ³³ äG

(30) ¤ ô MG

(31) o 210 µC/cm ³ ñ(, { Ñ Gñ roughness factorÍ _ê[9, 12]. dry. wet. 4. 2. 6. 2. 2. 4. 4. 2. Q Roughness factor= ---------------Qm × A. (3). Qm: 210 µC/cm2. M

(32) J ×s 0g »´, capacitive charge CV ê³z, −0.3 V-0.0 V « «O@ Ä

(33) s M,

(34). A: Q:. ¤@¤ C43× C1 2005 2. Fig. 3. Cross-sectional optical microscopy image of (a) Nafion 117 and (b) PPy/Nafion composite membrane..

(35) ·-)»³ í0ê SPE Mñk. 121. Gñ +_ê. àê ¤Q K

(36) o 200-250 ml/min«, 1 atmÑ ÒMæÉ. .M(Q ÍS, 52 5ÆQ,Ñ Gñ f´æ, Q ¤ ÍS52 ÎÎ 85 C, 80 C« .M( 52 75 C«. Ks, , gÑ õê backpressure regulator(Tescom 44-2300)Ñ Gñ äFts ÆQ Gk, .M( Ds +_G[13]. o. o. o. 3.. ûG Z +{. | o dHJ OYrs «ÄGñ PPy/Nafion Ls fÆGÊ

(37) s ³ K ,«. =Ñ < ¤ À 3-1. PPy/Nafion. Fig. 3 optical microscopy. Fig. 5. Ionic conductivity for PPy/Nafion composite membrane as a function of polymerization time.. ×« Nafion LÑ ·-)»« æ´ Àk

(38) æ+Ñ ]j Ý«2 z~« ·-)»»s < ¤ À. K, ·-)»« OYæ

(39) Nafion ,

(40) Ñ Âj2 s <4Ý, .g AFM ,s Fig. 4 Ñ ÷É. Fig. 4 êÑ < ¤ À×« Nafion ,

(41) Ý ·-)»s OY PPy/Nafion L ,

(42) «

(43) GÊ, ·-) »« Nafion L ,

(44) Ñ Êíj ~¯GÊ À{s e¯O ¤ ÀÉ. Nafion LOs ÄGñ dHJ hòÑ K Wzs e¯K ê, @ o L,

(45) Ý2 ÄUÑ

(46) ,}æ Nafion L,

(47) Ñ Wzê ñk j t(2 s ÷É. 6÷ ·-)»« OYê Nafion ,

(48) Mr,Í ÝWÑ g GÊ ÄUs dHJk³ hòGñ »o ¤So ·-) »s ÄG( :Is ÎÝ . «2 ·-)»« Nafion ,

(49) Ñ æ´ ,

(50) Mr,Q2 îÇ« ñkQ [ñt s Í ¤ À2 ak³ ¶ê. K, « hòî ) @ æ2 MÉÍ ·-)»³ Mî ¤ À´ @ « Ä«g(2 ak³ @Îê. Fig. 52 )» OYÑÑ ñ PPy/Nafion L «5 M ¡dõ ÷2 ê«. »)Ark³ +_K Nafion 117 «5M2 0.0779 S/cm³ éËj 0.08 S/cmQ WUK ê. Fig. 4. AFM images of Nafion 117 and PPy/Nafion composite membrane surfaces. (a) Nafion 117 (b) PPy/Nafion composite. Fig. 6. Water uptake contents for PPy/Nafion composite membrane as a function of polymerization time. Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005.

(51) 6_åö19 ö6K öáÜDöK_Îö«ã>öÆ³. 122. õ »s ¤ ÀÉ[14]. ·-)» OY íf³ FeCl õ ÄGñ fÆK PPy/Nafion Î2 «5 M ó«Í ¿( :Ik, Na S O s ÄGñ fÆê PPy/Nafion «5 M2 ·-)» OYÑ« ÍWÑ ¶ ÝG. K, Fig. 6Ñ )» OY ÑÑ ¶ fÆê PPy/Nafion W¤Ss ÷É. ·-)» O Y íf³ Na S O s ÄK PPy/Nafion W¤So )» OY Ñ« ÍO¤´ ÝG2 s Ý. ³äJk³ «5 M 2 W¤Sê WUK s Ý«2) á ×Ñ Na S O s. ÄGñ fÆê ·-)»o OY Ñ« ÍO¤´ W¤S« Ý GÊ «5 M ò ÝG2 as < ¤ ÀÉ. 6÷ FeCl Î «5 M2 W¤S« ÝWÑ ¶ ÝG( : Ê K(æ2 as e¯O ¤ ÀÉ. «2 ·-)»Ñ Nafion ÄU ê ço M¬ {«5s Í, í0s ?Gñ »o ·-)» L« «5 GhU s ÷2 ê[1, 4, 5] Ùê K K «K¶ 0 ê. M¬{«5k³ ?ê ·-)»o «5 Gh U « «5 GhU « Î§K asF Nafionê ·-)» OY K «5 Gh U « ÷÷2 ak³ 0ê. 6÷ ífÑ ñ M ó«Ñ ¬K «K2 ej :(O, NafionÑ OYê · -)» dU « ífÑ ¶ õ a«¶Ê @Îê. 3-2. Pt/PPy/Nafion (´ÿ O, | )» OY ÑÑ ñ Wz s <4Ý, .g í f³ 0.1 mol/L Na S O õ ÄGñ ÎÎ 5, 10, 20, 30~ 8 ) »s äE PPy/Nafion Ls fÆG. fÆê PPy/Nafion L s «Ñ &Ê K\ Ñ2 5 mM H PtCl ÄU 2 mlõ ÄGÊ ä¬\ Ñ2 0.5 M NaBH ÄUs ÄGñ 40~ 8 äE s WzG. )» OY Ñ« 5 min¯ Î2 NafionOs. ÄK ÎQ K÷Í(³ L ,

(52) Ñ Wz« ³´÷( :I. «ao )» OYÑ« J´ £~K Ê~É Y « ³´÷( : 4 WzÑ 1®K ³õ fàG( \K ak³ 0ê. )» ä Ñ« 10~Ñ 30~>(2 .

(53) J¢ ÎÎ 0.22, 0.22, 0.23 mg

(54) s gO ¤ ÀÉk 44-46% ¤S³ )» OYÑ Ñ s ç( :I. «2 ·-)» á Nafion ,

(55) Ñ « Wzæ2 ³fào )» OY ÑÑ2 åîWs < ¤ ÀÉ Ê, Äæ2 ÄU« JÊ Wz Ñ« ¬Jk³ ¿ 3. 2 2. 8. 2 2 8. 2 2. 8. 3. 2 2. Fig. 8. Cyclic voltammograms of Pt/PPy/Nafion with polymerization time of pyrrole using ferric chloride (Scan rate: 40 mV/s). Table 1. Amount of Pt loading, electricity, roughness factor, and surface area of Pt/PPy/Nafion composite electrodes with polymerization time of pyrrole Initiator Na2S2O8. 8. 2. FeCl3. 6. Time [min] 10 20 30 10 20 30. Pt loading Electricity Roughness Surface area [mg/cm2] [mC/cm2] factor [m2/g] 0.22 3.19 15.19 6.90 0.22 3.02 14.38 6.54 0.23 3.37 16.05 6.98 0.66 42.74 203.52 30.84 0.71 50.60 240.95 33.94 0.67 58.45 278.33 41.54. 4. , )éÑ Wz

(56) « ³_K ak³ 0ê. FeCl s íf ³ ÄGÊ )» OYÑ« 5, 10, 20, 30 min¯ PPy/Nafion ÞY Ls ÄGñ 5 mM 4 ml ÄUs ÄGs Î loading o .

(57) J¢ ÎÎ 0.50, 0.66, 0.71, 0.67 mgk³ sodium persulfateÑ Wg o 50-71% ¤Ss ÷É. «2 sodium persulfate Ý FeCl íf³ OYê ·-)» dU ¡dÍ ¬Jk³ ¿, )éÑ @ Ñ Ã s Ùj2 ak³ @Îê. «ao Nafion L« )»

(58) Q Fe «5 \Ñ ¬g ndt« âk³ & í0« Nafion Ls 0g eæ 2 Ñ ¿j s ç, )é³ a«[15]. Wz

(59) Ñ ¬ K )» OY Ñ s <4Ý, .g, ·-)» OYÑÑ ¶ fÆê Pt/PPy/Nafion M CVõ Fig. 7ê Fig. 8Ñ ÷É. Mg0 ÄUo 0.5 M H SO õ ÄGÊ ? 2 40 mV/s«É . CV êÑ < ¤ À×« Î Mo ¤Ñ ¬K »K ô Ú %ô )¿³z ·-)»« OYê Nafion ,

(60) l « K(æ2 as < ¤ ÀÉ. CV =Ñ −0.3 V-0 V « «O@ Ä

(61) s MG

(62) k³z Mr, ¯É Ú W,

(63) Js FeCl Ú Na S O ÎÎ dfÑ ¬g Table 1Ñ _-g I. Sodium persulfate Ý FeCl õ ÄGñ fÊê Pt/PPy/Nafion M l W,

(64) J« Î¤Ws < ¤ ÀÉk, Na S O Î (

(65) ê K Gj Mr, ¯É Ú W,

(66) J« )» OYÑ Ñ îÇ« WUK às ÷É. Fig. 9Ñ ·-)»« OYê Nafion L ,

(67) Ñ @ ê s ÷ 2 SEM ,s ífQ

(68) Ñ ¬g ÷É. )» ä 3. 3. 3+. 2. 3. 2 2. 4. 8. 3. 2 2. Fig. 7. Cyclic voltammograms of Pt/PPy/Nafion with polymerization time of pyrrole using sodium persulfate (Scan rate: 40 mV/s).. ¤@¤ C43× C1 2005 2. 8.

(69) ·-)»³ í0ê SPE Mñk. 123. Fig. 10. I-V curves for Pt/PPy/Nafion electrode with different Pt loading.. K ÎÝ Î¤Ws < ¤ ÀÉk, ,

(70) ½É2 g Hk³ æÊ ÀÊ @o ,

(71) ê ¤) ök³ æÊ À{s e¯O ¤ ÀÉ. ½É ¿,2 1 µmÝ ÊÊ @ 3 µm «G³ æÊ À. «sF Fig. 92 ·-)»s NafionÑ OYE s dHJk³ ( O Î, NafionÑ @ ê ·-)»« ÄU hòÑ g @ æ2 MÉõ H ¤ À2 í0³ ÊÄO ¤ À2 as HJk³ Ñ ÷Ê À. 3-3. !OO |ð l` ·-)»« OYê Nafion .Ñ ê ñk õ0M( Ä s <4Ý, .g . ¯Ñ ¬K õ0M( Ds +_G. ÍSê Q ¤ 52 85 C, 80 C «Ék, .M( 52 75 C³ G. ·-)»« OYê Nafion L .³ ñk @ê ÍA e@k³ g ê . MEA M

(72) Jo 2×2 cm ³ fÊG. Fig. 10o ·-)» OYÑ« 30 min¯ PPy/Nafion ÞY L Ñ 5 mM H PtCl ÄU 2, 4 ml z)³ fÊK Pt/PPy/Nafion M Ñ ¬K .M( Ds ÷É. Mo Pt/PPy/Nafion M ê e@k³ g æ´ Àk, Î M (

(73) s ªg I. FeCl ³ OYK PPy/Nafion ÞY LÑ ê ñk ³ fÊê MEA . D« Na S O íf³ fÊê MÝ Î¤K as < ¤ ÀÉ. «6K D ó«2 ·-)»³ í0 ê ÞY L «5 M ó«Ñ K a«M÷, 2 ê «÷ l Ñ K ó«³ @Îê. )» df³ FeCl ³ ÄK Î M¬ õ0M( Do 0.3 VÑ 569 mA/cm MÍàs ÷ÉÊ, (

(74) « Q40¤´

(75) Ï Ã MÍàs ÷ Ê À. «2 Table 1Ñ < ¤ À×« ço « 5ÄUs ÄGs Î (

(76) « Qs¤´ l W ,

(77) J « ÍG, MÑ ñkl « 42s Ýñ?Ê À. 6 ÷ õ0M(Ñ l W,

(78) Jo ä ¬Ñ ÊéG2 l ñkÑ g D« æÎæ³, CV³ Íê W,

(79) J ê2 ó«Í Às ak³ @Îê. ¶ U Ñ ,}ê CV ÍQ õ0M(Q Ds )[Jk³ õªÿ,2 å-Í o. o. o. 2. 2. 6. 3. 2 2. 8. 3. 2. Fig. 9. SEM images of surface and cross-section for Pt/PPy/Nafion electrode. (a) Pt/PPy/Nafion electrode prepared with Na2S2O8, (b) Pt/PPy/Nafion electrode prepared with FeCl3, and (c) Pt/ PPy/Nafion electrode prepared with FeCl3.. Ño 30~«Ék 5 mM H PtCl 4 mlõ ÄGñ fÊê Pt/ Mk³, Fig. 9(a), (c)2 FeCl õ Fig. 9(b)2 Na S O s íf³ ÄK Î«. ,

(80) SEM , ò FeCl õ. ÄK Î (

(81) ê ,à « Na S O s íf³ Ä 2. PPy/Nafion. 6. 3. 2 8. 3. 2 8. 8. 8. Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005.

(82) 6_åö19 ö6K öáÜDöK_Îö«ã>öÆ³. 124. À(O, Ds +O ¤ À2 1óJ¯ Írk³2 KÄO a« . Fig. 10ÑsF ·-)»³ í0ê Nafion LÑ ñkõ ) [Jk³ fÆO ¤ ÀÉÊ õ0M(³ ÄÍD s e¯O ¤ ÀÉ. 4.. û «. )»s dHJ OYrk³ NafionÑ WzE PPt/PPy/Nafions fÆGñ M,dHJ U Í Ú õ0M( D×Ñ Gñ {ê ço êõ »É. )»s dHOYrk³ NafionÑ OYG ñ fÆK PPy/Nafion L W¤So )» OY ÑÑ ¶ Ý Gk, «5 M2 FeCl õ íf³ ÄK Î ³_G k Na S O Î ÝG2 s Ý. K, )»« OY ê ÞY Lo ·-)» MÉ M s x2 U Ñ g ÄU hòäÑ @ ê MÉõ MG2 òO³ ÊÄGñ ,Ê T-Tr Ý Î¤K Wzs »s ¤ ÀÉ. fÆê M õ0M(³ Äs ]K ê, FeCl õ íf³ ÄK Î D« Î¤Gk õ0M( DËo 0.3 VÑ 569 mA/cm MÍàs ÷É. 3. 2 2. 8. 3. 2. [ ÷ « áéo. ¸ H¬,é (òÑ g õgæÉk «Ñ Ý Ã?n.. 2003 (KRF-2003-005-D00002). +S 1. Shimidzu, T., Ohtani, A. and Honda, K., “Dual-Mode Behavior in Doping-Undoping of Polypyrrole with Alkanesulfonate,” Bull. Chem. Soc. Jpn, 61(8), 2885-2890(1988). 2. Yatsuda, Y., Sakai, H. and Osaka, T., “Anion Doping-undoping Process of Electrochemically Polymerized Polypyrrole Film,” The Chemical Society of Japan, 7, 1331-1336(1985). 3. Somani, R. R. and Radhakrishnan, S., “Electrochromic Materials and Devices: Present and Future,” Materials Chemistry and Physics, 77, 117-133(2002). 4. Naoi, K., Oura, Y., Maeda, M. and Nakamura, S., “Electrochemistry of Surfactant-Doped Polypyrrole Film(I): Formation of Colum-. ¤@¤ C43× C1 2005 2. nar Structure by Electropolymerization,” J. Electrochem. Soc., 142(2), 417-422(1995). 5. Morita, M., Miyazaki, S., Ishikawa, M., Matsuda, Y., Tajima, H., Adachi, K. and Anan, F., “Layered Polyaniline Composites with Cation-Exchanging Properties for Positive Electrode of Rechargeable Lithium Batteries,” J. Electrochem. Soc., 142(1), L3-L5(1995). 6. Wang, L.-X., Li, X.-G. and Yang, Y. L., “Preparation, Properties and Applications of Polypyrroles,” Recative & Functional Polymers, 47, 125-139(2001). 7. Hirano, S., Kim, J. and Srinlvasan, S., “High Performance Proton Exchange Membrane Fuel Cells with Sputter-deposited Pt Layer Electrodes,” Electrochimica Acta, 42(10), 1587-1593(1997). 8. Choi, W. C., Kim, J. D7 and Woo, S. I., “Modification of Proton Conducting Membrane for Reducing Methanol Crossover in a Direct-Methanol Fuel Cell,” Journal of Power Sources, 96, 411414(2001). 9. O’Hayre, R., Lee, S.-J., Cha, S.-W. and Prinz, F. B., “A Sharp Peak in the Performance of Sputtered Platinum Fuel Cells at Ultra-Low Platinum Loading,” Journal of Power Sources, 109, 483-493(2002). 10. Millet, P., Durand, R. and Pineri, M., “Preparation of New Solid Polymer Electrolyte Composite for Water Electrolysis,” J. Hydrogen Energy, 15(4), 245-253(1990). 11. Liu, R., Hev, W. H. and Fedkiw, P. S., “In Situ Electrode Formation on a Nafion Membrane by Chemical Platinization,” J. Electrochem. Soc., 139(1), 15-23(1992). 12. Escribano, S. and Aldebert, P., “Electrodes for Hydrogen/Oxygen Polymer Electrolyte Membrane Fuel Cells,” Solid State Ionics, 77, 318-323(1995). 13. Lee, S. J., Mukerjee, S., Mcbreen, J., Rho, Y. W., Kho, Y. T. and Lee, T. H., “Effects of Nafion Impregnation on Performances of PEMFC Electrodes,” Electrochimica Acta, 43(24), 3693-3701(1998). 14. Yoon, S. R., Hwang, G. H., Cho, W. I., Oh, I. H., Hong, S. A. and Ha, H. Y., “Modification of Polymer Electrolyte Membranes for DMFCs using Pd Films Formed by Sputtering,” J. of Power Source, 106, 215-223(2002). 15. Schwitzgebel, G. and Endres, F., “The Determination of the Apparent Diffusion Coefficient of HCl in Nafion-117 and Polypyrrole+ Nafion-117 by Simple Potential Measurements,” Journal of Electroanalytical Chemistry, 386, 11-16(1995)..

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