Electrocatalytic Oxidation of Methanol and Ethanol by Carbon Ceramic Electrode Modified with Ni/Al L

催化学报2012Chinese Journal of CatalysisVol.33No.11Article ID: 0253- 9837(2012)11-1809-08DOI: 10.1016/S1872-2067(11)60452-XArticle: 1809- -1816Electrocatalytic Oxidation of Methanol and Ethanol by Carbon CeramicElectrode Modified with Ni/Al LDH Nanoparticles .Ghasem KARIM-NEZHAD , Sara PASHAZADEH, Ali PASHAZADEHDepartment of Chemistry, Payame Noor University, PO Box 19395-3697, Tehran, Iran .Abstract: A Ni/Al layered double hydroxide (LDH) nanoparticle modified carbon ceramic electrode (Ni/Al LDHNMCC) was fabricatedand used for the electrocatalytic oxidation of methanol and ethanol in alkaline media. Cyclic voltammtric (CV) studies showed that it gave asignificantly higher activity for methanol and ethanol oxidation and can be used as an electrocatalytic anode for fuel cells. The kinetic pa-rameters of the eletron transfer cofficient (a) and number of electrons involved in the rate determining step (na) for the oxidation ofmethanol and ethanol were determined using CV. The anodic currents showed a linear dependence on the concentration of methanol andethanol.Key words: nickel; aluminium; layered double hydroxide; modified carbon ceramic electrode; electrocatalytic oxidation; methanol; ethanolCLC number: 0643Document code: AReceived 10 July 2012. Accepted 30 August 2012.*Corresponding author: Tel: +98-461 -2349868; Fax: +98-461-2332556; E-mail: g.knezhad@ gmail.comEnglish edition available online at Elsevier ScienceDirect ht://ww.cencirec.comnscience/journa/18722067).Fuel cells have attracted much attention as an alternativecused on sol-gel derived carbon ceramic electrodes (CCES).power supply for many applications [1]. Research and deThese are generally prepared by doping graphite powdervelopment activites on direct alcohol fuel cells (DAFC)into a silicate gel matrix [16,17]. This electrode was devel-have increased tremendously in recent years. There are twooped in the early 1990s [18,19] and it is robust and easy toconventional types of DAFC: direct methanol fuel celprepare. A CCE can be easily modified by (i) doping the sol(DMFC) and direct ethanol fuel cell (DEFC) with methanolused for electrode preparation, (i) covalent modification ofand ethanol as fuel. Each fuel has advantages and disadvan-carbon microparticles, (ili) covalent modification of thetages. The disadvantages of utilizing methanol as a fuel aresol- gel precursor, and (iv) adsorption on the electrode sur-methanol crossover through the Nafion membrane to theface [18].oxygen electrode and anode poisoning by strongly adsorbedBecause CCEs have the advantages of low cost, high sta-intermediates (mainly CO) [2- :Ethanol is an alternativebility，good surface-renewal repeatability， and ease offuel because it can be produced from agricultural raw mate-preparation and modification, much work has been devotedrials, which helps diminish global concentrations of green-to preparing CCEs modified with different electrochemi-house gases. Ethanol has a lower crossover rate and impairscally active species [19cathode performance less than methanol [5].Layered double hydroxides (LDHs), which are hydrotal-Modified electrodes can provide electrochemists with thecite-like materials, are a class of two-dimensional nanos-ability to tailor electrode reactivity to obtain highly sensitivetructured anionic clays. The positively charged layers con-and selective signals [6]. Modified electrodes have recentlytain edge- shared metal M (II) and M (II) hydroxide octa-received much interest because they have a wide range ofhedra with charges neutralized by anions located in the in-potential applications in electrochemical technology, energyterlayer spacing or at the edges of the lamella. Elctrodesconversion, and chemical analysis, as well as possible apmodified with films of Ni/Al LDHs have attracted consid-plications in information storage, electrochromism devices,erable attention [19- -23]. Ni/Al LDH films have been re-and visual displays [7Modified carbon electrodes areported to catalyze the electrochemical oxidation of primarywidely used [8] because of their low background current,alcohols and sugars [24,25]. They have been used as ionwide potential window, chemical inertness, low cost, andselective electrodes for the potentiometric sensing of anionsthey are suitable for many applications [9-11]. Sol-gel elec-such as nitrate a中国煤化工amperometrictrochemistry has drawn extensive interest over the pastsensing of meth:YHCNMHG[27].Wangetdecades for its remarkable uses in electrochemical studiesal. have reported' the use ot a N1/AI LDH 1lm modified GCand applications [12-15]. Increasing interest has been fo-electrode for the electrocatalytic oxidation of methanol [28].1810催化学报Chin. J. Catal., 2012, 33: 1809- -1816The purpose of the present work is to prepare a Ni-AlLDH/NMCC electrode was as follows. MTMOS (0.2 ml),LDH nanoparticle modified carbon ceramic electrode andmethanol (0.6 ml), and 20 μul HCl (11 mol/L) were mixedinvestigate its electrocatalytic properties for the oxidation ofand stirred for 2 min until a homogeneous gel solution ap-methanol and ethanol.seared. Then 0.5 g graphite powder and Ni/Al LDHnanoparticle powder in a ratio of 9:1 were added, and the1 Experimentalresulting mixture was shaken for an additional 5 min. Themixture was packed into a Teflon tube (5 cm length and 21.1 Reagents and instrumentationmm inner diameter) and dried for 48 h at room temperature.Then the electrode was polished with polishing paper andMethyltrimethoxysilane MTMOS) was purchased fromrinsed with distilled water. The bare carbon ceramic elec-Fluka and used without further purification. Methanol, HCl,trode was made by the same procedure but without addingethanol, high purity graphite powder, and the other reagentsthe Ni/Al LDH nanoparticles to the graphite powder. Theused were analytical reagent grade provided by Merck andelectrie contact was made with a copper wire through theFluka. All solutions were prepared with doubly distilledback of the electrode. Then the electrode was placed in 0.1water. Electrochemical measurements were carried out in amol/L NaOH and the electrode potential was cycled be-conventional threeletrode cell powered by an electro-tween 0 and 700 mV (VS Ag/AgC1) at a scan rate of 50 mV/schemical system comprising an AUTOLAB system withfor 5 cycles in a cyclic voltammetric regime until a stablePGSTAT12 boards (Eco Chemie, Utrecht, and The Nether-voltammogram was obtained.lands). The system was run by a PC using the GPES 4.9software. A platinum wire positioned as close to the work-2 Results and discussioning electrode as possible by means of a Luggin capillarywas employed as the counter electrode. The Ni/AlThe Ni/Al LDH nanoparticle modified carbon ceramicLDH/NMCC electrode was the working electrode. All po-(Ni/Al LDHNMCC) electrode was prepared as a new typetentials were measured with respect to the Ag, AgCl couple.of electrode. For the activation of the electrode surface, theAll experiments were performed at room temperature (25土electrode was placed in 0.1 mol/L NaOH and the electrode2°C).potential was cycled between 0 and 700 mV (vs Ag/AgC1)at a scan rate of 50 mV/s for 5 cycles in a cyclic voltam-1.2 Preparation of Ni/Al LDH nanoparticlesmetry regime. Next the cyclic voltammograms of the modi-fied electrode were recorded in 0.1 mol/L NaOH at variousThe Ni/Al LDHs nanoparticles were prepared by thepotential sweep rates (Fig. 1(a). A pair of redox peaks washydrothermal method [29]. A series of Ni/Al LDHs with theobserved, which corresponded to the conversion betweennominal Ni t/A1*+ atomic ratio of 3/1 were prepared bythe different oxidation states of Ni by the reactionhydrothermal reaction at 180°C. All these were prepared asLDH-Ni(I) + 0H→LDH(OH )-NIiII)+e^ (1)follows. Appropriate amounts of NiSO4 6H2O ancWith the increase of the scan rate, the redox current in-Al2(SO4)3" 18H2O (Ni2+/Al+ = 3/1 molar ratio) were dis-creased, the anodic peak shifted toward positive potential tosolved in deionized water (40 ml). An aqueous solution ofoverlap with the oxygen evolution peak, and the cathodic0.5 mol/L Na2CO3 and 3 mol/L NaOH was added to thepeak was shifted toward negative potential. The currents ofabove solution dropwise with vigorous stiring to adjust thethe peaks (Ipa and Ip) were proportional to the sweep ratespH of the solution. After that, the suspension was trans-in the range of 3-100 mV/s (Fig. 1()), which showed theferred into a 50 ml stainless steel Teflon-lined autoclave andelectrochemical activity of the surface redox couple. Theheated at 180°C for the appropriate time, and then cooled tovalue of T was 1.31 X 10+ mol/cm2 for n= 1, which wasroom temperature naturally. The resulting product was fil-calculated from the slope of anodic peak current versus scantrated and washed several times with distilled water andrate using [30]:absolute ethanol. The apple-green solid was then dried atIp = (nF2/4RT)VAI(I)room temperature for 12 h. XRD results [29] indicated thatwhere v is the sweep rate, A is the geometric surface area,the size of the Ni/Al LDH particles was on the nanoscale.and I is the surface coverage of the redox species.An objective of the present study was to fabricate a1.3 Preparation of Ni/AI LDHNMCC electrodemodified electrc中国煤化工、oxidation ofmethanol and etlectrocatalyticYHCNMHGUnmodified and modified carbon ceramic electrode elec-activity of thecyclic volt-trodes were prepared using the procedure described byammograms were obtained in the presence and absence ofTsionsky et al. [18]. The fabrication procedure of the Ni/Almethanol at the bare (Fig. 2(1)) and Ni/Al LDHNMCCwww.chxb.cn Ghasem KARIM-NEZHAD et al.: Electrocatalytic Oxidation of Methanol and Ethanol by Carbon Ceramic Electrode 18111500 [cating that the anodic oxidation of methanol was catalyzed| (a(14)at the Ni/Al-LDH/NMCC electrode. The same behavior was1000observed for ethanol at the surface of theNi/Al-LDH/NMCC eletrode (Fig. 3).(1I1200(2900-500600300-1000 L(1)0.20.0.6.80E/(V vs Ag/AgCl)2000 [1500b)-300600 L.0).20.41.0500y= 15.40x+ 107.1是0R'=0.996Fig. 3. Cyclic voltammograms of bare carbon ceramic (1) and1000 ty=-14.5x- 121.5Ni/AI-LDHNMCC (2) electrode in 0.1 mol/L NaOH containing 0.05-1500 F R2 =0.99mol/L ethanol.-2000L-204080100 120Figure 4 shows the dependence of the voltammetric re-v/m/(V/s)sponse of the Ni/Al-LDH/NMCC electrode on the methanolFig.1. Cyclic voltammetric curves of Ni/Al LDH/NMCC electrodeconcentration, which showed an increase in the anodic peakin 0.1 molL NaOH at various potential scan rates (() 3 mV/s, (2) 5current and a decrease in the cathodic peak current. The plotmV/s, (3)7 mV/s, (4) 15 mV/s, (5) 20 mV/s, (6) 25 mV/s, (7) 30 mV/sof I versus methanol concentration was linear in the con-(8) 40 mV/s, (9) 50 mV/s, (10) 60 mV/s, (11) 70 mV/s, (12) 80 mV/s,centration range 10- 100 mmol/L. Similar cyclic voltammo-(13) 90 mV/s, and (14) 100 mV/s) (a) and anodic and cathodic peakgrams were observed for ethanol and the anodic peak cur-currents vs scan rate (° and。) and trendilines(- ) (b).rents depended on ethanol concentration in the range of10-100 mmolL (Fig. 5).(Fig. 2(2)) electrodes. At the bare electrode, no anodic cur-To get information on the catalytic mechanism, the cyclicrent due to the oxidation of methanol was observed. How-voltammograms of 0.050 mol/L methanol and ethanol atever, for the Ni/AI-LDH/NMCC electrode, a large anodicpeak was observed. Compared with the bare carbon ceramic1500 1400electrode, the electrochemical oxidation of methanol was)= 4.983.x + 524.6greatly increased at the Ni/AI-LDH/NMCC electrode, indi-R?= 0.99110)|至1000 |800( (2E 500400030.6090120Concentration (mmol/L1)|00 t1).4500 L中国煤化工E/(V vs Ag/AgCI)Fig.2. Cyclic voltammograms of bare carbon ceramic (1) andFig. 4. Cyelic .MYTHCN M H nentaios ofmethanol at the N. .nol/L NaOH at aNi/AI-LDH/NMCC (2) electrode in 0.1 mol/L NaOH containing 0.05scan rate of 50 mV/s. Concentrations of methanol for (1) to (10) weremolL methanol.0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, and 0.1 mol/L.1812催化学报Chin. J. Catal., 2012, 33: 1809- -1816equation [32].1500t y= 3.819x+ 783.7Ep = b/2logv + constant(I)1200 FR2 = 0.990(1(From Eq. (I), the slope of Ep versus logv is b/2, where b isthe Tafel slope. The slope of the plot of Ep versus logv is10008E,C(ogv), which was found to be 78.119. So b= 156.238,800which was in good agreement with the value obtained from600the polarization measurements. This slope indicated that a(1Concentration (mmol/Lone electron transfer process is the rate limiting step as-suming a transfer coefficient of a = 0.37. For ethanol, simi-lar results were obtained with a calculated transfer coff-cient of 0.42.-500We present the effect of NaOH concentration on metha-nol oxidation at the Ni/AI-LDHNMCC electrode in Fig. 6.-100With an increase in OH concentration, the peak current of).20..6methanol oxidation increased first and then began to de-E/(V vs Ag/AgC)crease remarkably at a NaOH concentration of 0.1 mol/L.The results indicated that the OH ion participates in theethanol at the Ni/Al LDH/NMCC electrode in 0.1 mol/L NaOH at aoxidation of methanol and was detrimental to the oxidationscan rate of 50 mV/s. Concentrations of ethanol for (1) to (10) wereof methanol because of competitive adsorption with metha-0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, and 0.1 mol/L.nol for the active cites. At a high OH concentration(> 0.1mol/L), the current mainly came from the redox of thedifferent scan rates were recorded (not shown). The anodicNi(II)/Ni(I) couple because of the competitive adsorptionoxidation current with methanol was proportional to theon the active sites by OH . To get a high oxidation current atsquare root of the scan rate, indicating that at a sufficientlya lower oxidation potential, 0.1 mol/L NaOH was chosen aspositive potential, the reaction was controlled by methanolthe support electrolyte. For ethanol, similar results werediffusion. This is the ideal situation for quantitative applica-obtained and shown in Fig.7.tions.In Fig. 8, the Tafel slopes for the electro-oxidation ofIt was also observed that by increasing the sweep rate, themethanol at the Ni/AI-LDHNMCC electrode for variouspeak potential for the catalytic oxidation of methanol wasNaOH concentrations are shown. Figure 8 shows that theshifted to more positive values and the plot of peak currentmechanism of the oxidation changed for NaOH concentra-versus square root of scan rate deviated from linearity, .which suggested kinetic control in the reaction between the1200redox sites of the modifier and methanol. These resultsshowed that the cross exchange process between methanol00至600and the redox sites of the Ni-Al LDH couple and the diffu->(6sion of methanol controlled the overall electrochemical00 F200，oxidation of methanol at the Ni/AI-LDH/NMCC electrode.5(4The same results were observed with ethanol.s 300-0.0 0.1 0.2 0.3 ,2(3It has been reported in the literature [31] that this behav-7(2ior is typical of the mediated oxidation of methanol and7(1ethanol, which areLDH-Ni (I) + 0H←LDH (OH )-Ni(II)+e~ (2LDH (OH )-Ni (I) + alcohol→LDH-Ni (I)+ OH +oxidation products(3To get information on the rate determining step, a Tafel-600 L.00.40.8slope was drawn using data from the rising part of the cur-rent voltage curve recorded at a scan rate of 5 mV/s. A slopeof 120.6 mV per decade was obtained, which indicated thatFig. 6. Cyclic vo中国煤化工，-NMCC electrodea one electron transfer was involved in the rate limiting stepin 0.05 mol/L metations of NaOHassuming a charge transfer coefficient (a) of 0.49. The Tafelat the scan rate ofYHCNMHGmwas0.01(1)slope was also obtained from the linear relationship ob-0.02 (2), 0.03 (3), 0.05 (4), 0.08 (5), 0.1 (6), 0.2 (7), and 0.3 (8) molL.served for Ep versus logv (not shown) by the follwingThe inset displays the peak currents Vs NaOH concentration.www.chxb.cn Ghasem KARIM-NEZHAD et al.: Electrocatalytic Oxidation of Methanol and Ethanol by Carbon Ceramic Electrode 18131200presence of two different mechanisms operating simultane-ously. On the other hand, the Tafel slope did not change at900 fthe NaOH concentration of 0.1 mol/L for different methanol900女7(6concentations, and it was 0.120 V/decade. This means that走600为(8a unique mechanism that does not depend on the methanol600一 300力concentration operates at the NaOH concentration of 0.1mol/L, and the rate determining step is the first electron0.0 0.1 0.2 0.324)手300Concentration (mmol/L)>3)transfer [33]. For ethanol, similar results were obtained (not32)shown). For the NaOH concentration of 0.1 mol/L, the Tafelslope was 0.120 V/decade. At NaOH concentrations of 0.05,0.02, and 0.01 molL, the Tafel slopes were 0.140, 0.170,and 0.229 V/decade, respectively.-300The reaction kinetics of the oxidation of methanol andethanol on the Ni/Al-LDH/NMCC electrode was investi--600gated by chronoamperometry. Double step chronoampero-.20.40.0.8grams were recorded by setting the working electrode po-E/(V vs Ag/AgC)tentials to the desired values, and these were used to meas-Fig. 7. Cyelic voltammograms of the Ni/Al LDH/NMCC electrodeure the catalytic rate constant on the Ni/AI-LDH/NMCCin 0.05 mol/L ethanol containing different concentrations of NaOH atelectrode surface. Figure 9(a) shows the double stethe scan rate of 50 mV/s. The NaOH concentration was 0.01 (1), 0.02chronoamperograms for the Ni/Al-LDHNMCC electrode in(2), 0.03 (3), 0.05 (4), 0.08 (5), 0.1 (6), 0.2 (7), and 0.3 (8). The inset .the absence and presence of different concentrations ofdisplays the peak currents vs NaOH concentration.methanol at the oxidation potential of 710 mV against theAg/AgCl couple. Figure 9(b) shows the plot of the current attions in the range of 0.01 -0.1 mol/L because the Tafela fixed time interval of 15 s versus the concentration ofslopes were different. For the NaOH concentration of 0.1,methanol in the range of 0.01 to 0.08 mol/L. Good linearthe Tafel slope was 0. 1206 V/decade, which indicated a firstplots were observed. The plotting of net current versus mi-electron transfer depending on the applied potential as thenus square root of time gave linear plots (Fig. 9(c)). There-rate determining step. At NaOH concentrations of 0.05,fore, a diffusion controlled process dominated the electro-0.02, and 0.01 mol/L, the Tafel slopes were 0.136, 0.170，catalytic oxidation of methanol.and 0.242 V/decade, respectively, and could indicate theThe ratio of the transient current in the presence ofa)b)|.6 F0.6F0.5 E昏0.4Fy= 0.120x+ 1.0540.3Fy=0.136x+ 1.144R =0.992.R? =0.9880.0 L0.0L-5.5-5.0-4.5-3.5-3.0-4.03.5log//Algl/A.6-2.0c)|(d) |1.6-.2 F0.8-).4-y= 0.170x + 1.352y= 0.242x+ 1.741R =0.987R = 0.984.5-5.-4.-5.50 -5.25中国煤化工-4.00YCNMHGFig. 8. Tafel slopes obtained for methanol oxidation at the Ni/Al LDHNMCC electrode at different NaOH concentrations. The concentration ofmethanol was 0.05 mol/L. Potential sweep rate was 5 mV/s. (a) 0.1 mol/L NaOH; (b) 0.05 mol/L NaOH; (c) 0.02 mol/L NaOH; (d) 0.01 mol/L NaOH.1814催化学报Chin. J. Catal, 2012, 33: 1809- -1816a)700(b1600600 t500 f1200 t兰400-00 H300 f)|y= 5.091x+ 19400 F200 FR'= 0.995100 F0 20306(4C8000Concentration (mmol/L)000(c)8) |.0一 (d).5-.0-1)|y=1.191x + 0.19500 tR2=0.9900.0).10.20.).50.6.01.52.02.5Fig. 9. Chronoamperograms of the Ni/Al LDHNMCC electrode in 0.1 mol/L NaOH solution in the absence (1) and presence (2- 9) of concentra-tions of methanol of 0.01 (2), 0.02 (3), 0.03 (4), 0.04 (5), 0.05 (6), 0.06 (7), 0.07 (8), and 0.08 (9) mol/L, respectively (a); chronoamperometric cur-rents att= 15 s versus concentration of methanol (b); dependence of transient current on f 12 (c); dependence of la/Is on t42 derived from the CAs of(1) and (10) in panel.methanol to the limiting current in its absence is [34]of Nilll increased and reached a saturation (steady state)Ia/Is= ("((Ierf(212) + exp(-)n!")) (II)level, and the oxidation current followed accordingly. Ac-where Lcat is the catalytic current in the presence of metha-cording to Eq. (V)nol, Ia the limiting current in the absence of methanol and λig= 2FAkpTkzcm/(k + k2 + 2k2Cm)= kct (k, c, and t are the catalytic rate constant, bulk concen-The plots of the inverse current against inverse methanoltration of methanol and the elapsed time, respectively) is theconcentration should be linear [36]:argument of the error function. For h > 1.5, erf(."2) almostif' =(FAk|D)'+ ((k +k )/2FAKk2D)cm (VI)equals unity and Eq. (3) reduces to [35]Figure 10(b) presents the plots of i versus cm whereIex/la=λl"rl2 = π"?(kcr)"2(IV)straight lines at various potentials were obtained. Both theFrom the slope of the LaI vs l"plot, the value of k forintercepts and slopes of the straight lines in this figure were0.07 mol/L methanol was calculated to be 0.6453 x 104potential dependent.cm' /(mol.s) (Fig. 9()). Similar chronoamperograms wereThe slopes were plotted against exp(-nFE/RT) withn= 1collected for ethanol. The value of k for 0.06 mol/L ethanoland presented in Fig.10(c). Using this graph along with Eq.was 0.1198 x 10* cm'/(mols).(VI) gave the rate constant of reaction, k2T. The ratio ofThe pseudo-steady state polarization curves of the elec-R'_1h2! were 3.66x 109 cm/s and 8.87 x 10° respectively.tro-oxidation of methanol on the Ni/Al LDHNMCC elec-Figure 10(d) presents the variation of the intercepts of thetrode at a number of methanol concentrations are presentedlines in Fig. 10(b) with the applied potential on a semi-login Figure 10(a). The rotation rate of the electrode waplot. Using this graph and Eq.(VI), k'r and the anodicmaintained at 3000 r/min to avoid the interference of masstransfer coefficilroroer 4.16 x 1transfer in the kinetics measurements. The oxidation beganmol(s. cm) and中国煤化工Suts were ob-at 483.4 mV (VS Ag/AgCI) and reached a plateau at 684.8tained. The valueC N M H Gobtained weremV (vs Ag/AgCI) while oxygen evolution started at still1.23x 109 cm/s, 2.38x 10, 1.64x 10~-"0 cm/s, 8.09x 10',higher potentials. In the course of the reaction, the coverageand 0.4, respectively.www.chxb.cn Ghasem KARIM-NEZHAD et al.: Electrocatalytic Oxidation of Methanol and Ethanol by Carbon Ceramic Electrode 1815(a8)24000b)(1)00 F160004001)800000 t).40.0.8206080E/VCm '([/mol)10.0(c).5-50.0 F40.5 F8.0 Fy-=23.55.x+ 21.40y= 1E+10x+ 11.26R =0.994R2= 0.993.0 40.00E+000 1.00E-009 2.00E-009 3.00E-009 4.00E-0090.480.500.520.54 0.560.58Exp(-nFEIRT)Fig. 10. Pseudo steady state polarization curves of the Ni/Al LDH/NMCC electrode obtained in 0.01 (1), 0.02 (2), 0.03 (3). 0.04 (4), 0.05 (5), 0.06(6), 0.07 (7), and 0.08 (8) molL methanol (a), plots of r against cm-' at various potentials of 503.5 (), 513.6 (2), 523.7 (3), 533.8 (4), 543.8 (5),553.9 (6), 564 (7), and 574 (8) mV/Ag/AgCl (b), plot of the slopes (of curves in ()) vs exp(-nF EIRT) (c), and plot of the Ln(intercepts) (of curves in(b)) vs applied potential (d).7 ZenJ M, Kumar A S, Tsai D M. Electroanalysis, 2003, 15:3 Conclusions10738 Redepenning J G TrAC-Trend Anal Chem, 1987, 6: 18A Ni/AI-LDH/NMCC electrode was prepared and used) Mortimer R. J Chem Soc Rev, 1997, 26: 147for the electrocatalytic oxidation of methanol and ethanol.10 Farhadi K, Kheiri F, Golzanb M. J Braz Chem Soc, 2008, 19:The modified eletrode gave good activity for the elec-1405trooxidation of methanol and ethanol. The mechanism of the11 Sun D, Zhu L, Zhu G Anal Chim Acta, 2006, 564: 243oxidation changed with the NaOH concentration in the12 Wang J. Electroanalytical Chemistry. 2nd Ed. New York:range of 0.01 -0.1 mol/L. Good stability, good reproducibil-Wiley, 2000. 115ity, rapid response, and easy surface regeneration and fabri-13 McCreery R L. Electroanal Chem, 1991, 17: 221cation are the important properties of the new electrode.14 Wang B, Li B, Wang Z, Xu G, Wang Q, Dong S. Anal Chem,1999, 71: 193515 Salimi A, Pourbeyram S. Talanta, 2003, 60: 205References16 Walcarius A. Electroanalysis, 2001, 13: 7011PanWH,JessieLueS,ChangCM,LiuYL.JMembrSci,17 Wang J. Anal Chim Acta, 199. 399: 212011, 376: 22518 Tsionsky M, Gun J, Glezer V, Lev O. Anal Chem, 1994, 66:Ravikumar M K, Shukla A K. J Electrochem Soc, 1996, 143:1747260119 Miyata S. Clays Clay Miner, 1980, 28: 50; DuC Y, Zhao T s, Yang W w. Eletrochim Acta, 2007, 52:20 Reichle w T. J Catal, 1985, 94: 547526621 Xu Zh P, Lu G Q. Pure Appl Chem, 2006, 78: 771Heinzel A, Barragan VM. J Power Source, 999. 84: 70中国煤化工5,395: 159; Song S, Zhou W, Liang Z, Cai R, Sun G, Xin Q, Stergiopoulos23 Qiu J B, Vller7, 428: 165V, Tsiakaras P. Appl Catal B, 2005, 55: 6524 EhilissenIFYHC NMH GP, Figlarz M,6 Shankaran D R, Narayanan S s. Bull Korean Chem Soc, 2001,Willmann P. J Mater Chem, 1993, 3: 88322: 81625 Roto R, Villemure G. J Electroanal Chem, 2002, 527: 1231816催化学报Chin. J. Catal., 2012, 33: 1809- -181626 Roto R, Yamagishi A, Villemure G J Electroanal Chem, 2004,Anal Chim Acta, 2005, 538: 219572: 10132 Karim-Nezhad G Seyed Dorraji P. Electrochimica Acta, 2010,27 Scavetta E, Berrettoni M, Giorgetti M, Tonelli D. Electrochim55: 3414Acta, 2002, 47: 245133 Karim Nezhad G, Jafarloo R, Seyed Dorraji P. Electrochimica28 Wang Y, Zhang D, Tang M, Xu S, Li M. Electrochim Acta,2010, 55: 404534 Hasanzadeh M, Karim-Nezhad G, Shadjou N, Khalilzadeh B,9 Prevot V, Caperaa N, Taviot-Gueho C, Forano C. CrystalSaghatforoush LA, Earshad S, Kazeman I. Chin J Chem, 2009,Growth Design, 2009, 9: 364627: 63830 Karim-Nezhad G, Hasanzadeh M， Saghatforoush LA35 Zheng L, Song J. J Applelectrochem, 2011, 41: 63Shadjou N, Earshad S, Khalilzadeh B. J Braz Chem Soc36 Hasanzadeh M，Karimnezhad G, Mahjani M G Jafarian M,2009, 20: 141Shadjou N, Khalilzadeh B, Saghatforoush L A. Catal31 Ballarin B, Brrettoni M, Carpani I, Scavetta E, Tonelli D.Commun, 2008, 10: 295中国煤化工MHCNMH G