(ElectroCHemicalANalyzer, ECHAN) (Figure 1) - Savitzky-Golay. Koutecky-Levich DMFC. K4[Fe(CN)6], Mn Fe Co Ni Cu. (XC-72R) 50 wt%

Transcription

1 3 5 () Windows GUI MEA Nafion Pt Disk Nafion 2 ()

2 (1) (ElectroCHemicalANalyzer, ECHAN) (Figure 1) - (3) (2) FFT() Savitzky-Golay (4) () Figure 1 Screen shot of the control panel of ECHAN. (1) Koutecky-Levich Present track and Updown button for selecting a track. (2) Levich Combo box for the conversion between reference potentials Cottrell Coulomb Tafel (3) Information table for the present track. (4) Graph area of the present track. Pt Pt Pt DMFC Pt a) K4[Fe(CN)6], K4[Ru(CN)6], K4[Ir(CN)6](), K4[Pt(CN)6] (Aldrich) 4 TiVCr MnFeCoNiCu (XC-72R) 50 wt% Ar M H2SO4 Cyclic Voltammetry (CV) RRDE Ar XRD 5% Scherrer Figure 2 Ru(CN)6 8 8 Ir Pt (1/n) Figure 2 Particle sizes of polycianide-based oxygen reduction catalyses estimated by Sherrer equation. Figure 3 Overvoltage at 1mAmg-1 corrected by the size of catalysis particles heat-treated at 800.

3 Figure 3 Ru(CN)6 CrFeCo Ir(CN)6 Ti Mn Pt(CN)6 Ni Fe Figure 4 FeIr(CN)6 20%-Pt-XC72R (Electrochem ) Pt FeIr(CN)6 b) [(bpy)2cuohcu(bpy)2] 3+ [(phen)2cuohcu(phen)2] mM -0.05M - Figure V vs. RHE [(bpy)2cuohcu(bpy)2] 3+ Potential /V vs. RHE ma cm -2 [(phen)2cuohcu(phen)2] Figure 5 Polarization curves for oxygen reduction using macm mm Cu complex in 0.05M sulfuric acid. Scan rate is F.C. Anson [Cu(bpy)2] 5mVs -1., [(bpy)2cuohcu(bpy)2] without methanol ; ---, [Cu(phen)2] [(phen)2cuoh (phen)2] without methanol,,[(bpy)2cuohcu(bpy)2] in 1 M methanol. Pt D.B. Sepa Tafel 60mV 120mV Pt Pt disk MEA Gauss-Newton A: (A) electrolyte solution (B) electrolyte solution phase 0 phase 1 phase 0 phase 1 Pt disk 0 l 0 1 l 2 x l 1 l 2 x Nafion film Pt/C/Nafion film Nafion Pt Disk (Figure 6(A)) Nafion (Figure 6(B)) Potential /V vs. RHE Disk / ma cm log 10 (i / A mg metal -1 ) Figure 4 Polarization curves for oxygen reduction with heat-treated polycyanide complex at varuous methanol concentrations. Rotating speed is 300rpm. Scan rate is 5 mvs -1. Pt disk electrode Glassy carbon electrode Ring / ma cm -2 Figure 6 Illustration of (A) a polymer coated electrode and (B) MEA coated electrode in an electrolyte solution.

4 (DMFC) 2 Figure 7 Polarization curves for oxygen reduction in 0.05M H 2 SO 4 at positive-going scan. Scan rate is 5 mv s -1. Rotating speed is 300 rpm. (a) 0.1mM bpy-0m MeOH; (b) 0.1mM bpy-0.1m MeOH; (c) 0.1mM bpy-1m MeOH; (d) 0M bpy-0m MeOH; (e) 0M bpy-0.1m MeOH; (f) 0M bpy-1m MeOH. 2 Figure 7(d)(e)(f) ( Ec ) V (0.1M ) V (1M ) 2% Figure 7(a)(b)(c) 0.1mM Ec V V Ec V (0.1 M MeOH) V (1 M MeOH) Ec +0.13V Table 1 0.8V (%H2O) Ec (jl) Cu2(phen)4OH (jo) Ec Ec Ec Table 1 Effect of additives on polarization curves for oxygen reduction and methanol oxidation a. additive b 0M MeOH 0.1M MeOH 1M MeOH Ec /V c jl /ma cm -2d %H2O e Ec /V c jl /ma cm -2d jo /ma cm -2g Ec /V c jl /ma cm -2d jo /ma cm -2g bpy bpy (0.4 mm) phen terpy dpphen Cr2(phen)4OH Fe(terpy)Clx f Ni2(bpy)4OH Cu2(phen)4O H ameasurements were performed in 0.05M H2SO4 at room temperature under 1 atm oxygen or nitrogen. Scan rate is 5mVs -1. Rotating speed is 300 rpm. b The concentrations of additives are 0.1 mm. c Potential at the cathodic current of A cm -2 real. ddiffusion limiting current of oxygen reduction at 0.3V vs RHE normalized by the geometrical area of a Pt disk electrode. eefficiency of O2 to H2O at 0.8V. f x = 2-3. g A peak current of methanol oxidation under 1atm N2.

5 Ec 2,2 - Figure 8 0.1M 2,2 - SEIRAS Pt IRRAS Pt SEIRAS 2,2-3670cm -1 ( OH )2,2- CO 2,2-2,2- CO 2 0.5V 1.5% 0.7V 1.0V 2,2- CO CO OCO 1320 cm -1 CO 2,2-2,2-Pt,2-2 Pt 2,2- Pt 2,2-2,2-2,2 - Pt CV 2,2 - Pt Figure 8 Series of SEIRA spectra of the Pt plating electrode in 0.1 M HClO4 at various potentials under N2...., in 0.1M CH3OH-0 mm bpy; ---, in 0 M CH3OH-0.1 mm bpy;, in 0.1M CH3OH-0.1mM bpy. (A) OH stretching band. Baselines were corrected from 4000 cm -1 to 2400 cm -1 linearly. (B) CO stretching band of linear and bridged CO on Pt. Baselines were corrected at 2400 cm -1 as zero at each potential. (C) HOH bending band, formate and perchlorate bands. Baselines were corrected at 2400 cm-1 as zero at each potential.

6 Open-source Electrochemical Measurement System Equipped with Macro Language for Successive Meausrement Hidenobu Shiroishi and Tatsuhiro Okada, J. Comput Chem. Jpn., 3 (2004) 71. Effect of Additives on Electrochemical Reduction of Oxygen in the Presence of Methanol Hidenobu Shiroishi, Yusuke Ayato, Keiji Kunimatsu, Tatsuhiro Okada Chem. Lett., 33, 792 (2004). Mechanism of Selective Oxygen Reduction on Platinum by 2,2 -bipyridine in the Presence of Methanol Hidenobu Shiroishi, Yusuke Ayato, Tatsuhiro Okada, Keiji Kunimatsu Langmuir, in press 3 16 Selective Oxygen Reduction on Platinum by Additives in the Presence of Methanol Hidenobu Shiroishi, Yusuke Ayato, Jiří Rais, Keiji Kunimatsu, and Tatsuhiro Okada 2004, 2004/10/06 DMFC Jiří Rais 45 (2E01)2004/11/ H16/02/ JIŘÍ RAIS