Electrodeposition of Ni nanoparticles from deep eutectic solvent and aqueous solution as electrocatalyst for methanol oxidation in acidic media

Electrodeposited Nano-Ni films at pencil graphite electrode from aqueous acetate buffer and Ethaline solvent as an example of deep eutectic solvents (DESs) were estimated as electrocatalysts for electrooxidation of 1 M methanol in 1 M H₂SO₄. The electrodeposition process and the electrocatalytic behavior of Nano-Ni films were performed using the chronoamperometry and cyclic voltammetry techniques, respectively. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and x-ray diffraction (XRD) were used for the characterization of Ni deposits from the two different solvents. It was found that Ni/PGE deposit from Ethaline gives 6.01 mA cm^?2 current density at anodic peak potential of 0.67 V and onset potential of 0.31 V while, Ni/PGE deposit from acetate produces 5.6 mA cm^?2 current density at anodic peak potential of 0.65 V and onset potential of 0.37 V, suggesting the higher catalytic activity of Ni/PGE from DES towards methanol oxidation.     

Electrocatalytic activity of nanostructured Ni and Pd–Ni on Vulcan XC-72R carbon black for methanol oxidation in alkaline medium

Ni and Pd–Ni nanoparticles were chemically deposited on Vulcan XC-72R carbon black by impregnation method using NaBH₄ as a reducing agent. The prepared electrocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). The electrocatalytic activity of Ni/C and Pd–Ni/C electrocatalysts towards methanol oxidation in 0.5 M KOH solution was examined using cyclic voltammetry and chronoamperometry. Two methanol oxidation peaks were observed on the Pd–Ni/C at 0 and +860 mV. Their current density values are higher than those at Pd/C and Ni/C electrocatalysts by 1.92 and 1.68 times, respectively. The catalytic rate constant of methanol oxidation reaction at Ni/C and Pd–Ni/C electrocatalysts in (0.2 M MeOH + 0.5 M KOH) solution was estimated using double-step chronoamperometry as 5.64 × 10³ and 6.25 × 10³ cm³ mol⁻¹ s⁻¹, respectively. Pd–Ni/C is more stable than Pd/C and Ni/C electrocatalysts. Therefore, Pd–Ni/C is a suitable as a less expensive electrocatalyst for methanol oxidation in alkaline medium.     

Catalytic activity of electrodeposited ternary Co–Ni–Rh thin films for water splitting process

The influence of the deposition parameters on the composition and structure of Co–Ni–Rh ternary alloys was studied. The catalytic activity of the coatings for the hydrogen evolution process was investigated in 6 M KOH electrolyte. The thin films were deposited from baths containing a mixture of Co²⁺, Ni²⁺, and Rh³⁺ chloride complexes. A wide range of alloy compositions were achieved by applying different deposition potentials from −0.5 to – 0.9 V vs SCE. The obtained coatings were examined by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) techniques. The surface morphology and chemical composition were also characterized with scanning electron microscopy (SEM) combined with EDX. The hydrogen evolution activity of some selected electrodes were examined in 6 M KOH using current-potential curve and electrochemical impedance spectroscopy (EIS) techniques. The SEM results showed that the surface morphology of the electrodes can be tailored by modification of the deposition potential. The higher exchange current densities were observed in catalytic measurements for the ternary alloys, which confirms their better catalytic activity in the water-splitting process.     

The formation of wrapping type Pt–Ni alloy on three-dimensional carbon nanosheet for electrocatalytic oxidation of methanol

In this paper, the PtNi alloy was embedded into the surface layer of three-dimensional carbon nanosheets (CNSs) with a special layered structure. We controllably adjusted the ratio of Pt/Ni to form large particle alloy with Pt coating Ni and a small number of hollow PtNi alloy pellets. The electro-catalytic methanol oxidation activity and durability of the catalysts were estimated by cyclic voltammetry and chronoamperometric techniques. The results indicated that the doping of Ni effectively improved the activity and anti-poisoning of the catalyst in the methanol electrocatalytic oxidation reaction (MOR). Transmission electron microscopy (TEM), Raman spectroscopy, nitrogen adsorption-desorption techniques, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to explore the composition, morphology and structure of these catalysts. It is discovered that the Pt–Ni/CNSs (2:1) sample exhibits the best MOR activity with a peak current density of 15.03 mA cm^?2 at the forward scan due to the excellent lamellar structure, good crystallinity and abundant pore structure of CNSs, which is benefit to form ultrahigh specific surface area, superb electron and ionic conductivity.     

Fabrication of three-dimensional copper nanodomes as anode materials for direct methanol fuel cells

In this study, we demonstrate a novel approach for fabricating copper nanodomes (Cu-NDs) by combining of soft lithography, nanosphere lithography, physical vapor deposition (PVD) and electrochemical deposition methods. The 3D nano structures were characterized using surface microscopic techniques. The methanol oxidation activity of the Cu-NDs anode was tested by electrochemical methods in 0.1 M KOH +1 M CH₃OH solution and the results were compared with that of bulk Cu as a reference point. The results showed that very well-structured, uniformly and homogeneously distributed Cu-NDs could be fabricated using these combined methods. The peak current density related to methanol oxidation reaction increased and charge transfer resistance reduced almost three times at the Cu-NDs electrode with respect to the bulk Cu. Also, the Cu-NDs electrode has good time stability and high tolerance to CO_ads poisoning. The enhanced activity of the nanostructures was related to good intrinsic activity of Cu for this reaction and their larger available electrochemical active sites.     

Hydrogen production from water–methanol solution over visible light active indium–titanium oxide photocatalysts modified with copper oxide

Titanium oxide coupled with different amount of indium oxides were studied for production of hydrogen under visible light irradiation from water–methanol solution. The photocatalysts were prepared by co-precipitation and characterized by surface area and pore analysis, X-ray diffraction, field emission scanning electron microscopy, UV–Vis diffuse reflectance spectra, and photoluminescence spectroscopy. With increases in indium oxide content, the surface area, visible light absorption and separation of photogenerated electron-holes were enhanced. For binary catalysts, the activity was highest for 16.7 at.% indium with hydrogen production of 1829 μmol/g/h. Incorporation of copper oxide further enhanced the activity with hydrogen production of 2149 μmol/g/h. The higher hydrogen production for ternary catalyst can be attributed to the synergistic effects of higher surface area, stronger absorption in visible light region and enhanced separation of photogenerated charge carriers. The hydrogen generation was attributed to partial oxidation of methanol to formaldehyde thereby producing pure hydrogen.     

Enhanced electrocatalytic performance of Pt nanoparticles immobilized on novel electrospun PVA@Ni/NiO/Cu complex bio-nanofiber/chitosan based on Calotropis procera plant for methanol electro-oxidation

Bioinspired Ni/NiO nanocomposite was synthesized in the Calotropis procera wood and its size and structure were confirmed by transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). The green and environmental friendly approach was performed for the preparation of copper nanocomplex (CC) under ultrasonic irradiation. Polyvinyl alcohol (PVA) nano-biofibers containing Ni/NiO nanocomposite and copper nanocomplex were obtained by electrospinning method. This novel bio nanocomposite was characterized by field-emission scanning electron microscope (FESEM), TEM, and atomic force microscopy (AFM) for further investigation. Novel Pt/PVA@Ni/NiO/Cu nanocomplex/chitosan (Pt/PVA@NOCC/CH) was synthesized and its catalytic performance was studied towards methanol electro-oxidation. Pt/PVA@NOCC/CH catalyst exhibits enhanced electrocatalytic performance towards methanol oxidation (MO), compared to Pt/PVA/CH and Pt/PVA@NOCC with respect to its better stability, larger electrochemically active surface area, enhanced mass activity, and improved resistance to poisoning. By and large, Pt/PVA@NOCC/CH is known as a promising electrocatalyst for fuel cells.     

Carbon-ceramic supported bimetallic Pt–Ni nanoparticles as an electrocatalyst for electrooxidation of methanol and ethanol in acidic media

The electrooxidation of methanol and ethanol was investigated in acidic media on the platinum–nickel nanoparticles carbon-ceramic modified electrode (Pt–Ni/CCE) via cyclic voltammetric analysis in the mixed 0.5 M methanol (or 0.15 M ethanol) and 0.1 M H₂SO₄ solutions. The Pt–Ni/CCE catalyst, which has excellent electrocatalytic activity for methanol and ethanol oxidation than the Pt–Ni particles glassy carbon modified electrode (Pt–Ni/GCE), Pt nanoparticles carbon-ceramic modified electrode (Pt/CCE) and smooth Pt electrode, shows great potential as less expensive electrocatalyst for these fuels oxidation. These results showed that the presence of Ni in the structure of catalyst and application of CCE as a substrate greatly enhance the electrocatalytic activity of Pt towards the oxidation of methanol and ethanol. Moreover, the presence of Ni contributes to reduce the amount of Pt in the anodic material of direct methanol or ethanol fuel cells, which remains one of the challenges to make the technology of direct alcohol fuel cells possible. On the other hand, the Pt–Ni/CCE catalyst has satisfactory stability and reproducibility for electrooxidation of methanol and ethanol when stored in ambient conditions or continues cycling making it more attractive for fuel cell applications.     

Promising anode candidates for direct ethanol fuel cell: Carbon supported PtSn-based trimetallic catalysts prepared by Bönnemann method

To find an efficient anode catalyst for ethanol electrooxidation, several trimetallic PtSnM/C (M = Ni, Co, Rh, Pd) and their corresponding bimetallic PtX/C (X = Sn, Ni, Co, Rh, Pd) catalysts were synthesized by Bönnemann's colloidal precursor method and evaluated by comparing their electrocatalytic activity using conventional electrochemical techniques. For better understanding of the catalyst deactivation during the ethanol electrooxidation, chronoamperometric test was also combined to X-ray photoelectron spectroscopy (XPS) analysis. A significant finding is that trimetallic compositions PtSnCo/C and PtSnNi/C have enhanced activity compared to that of PtSn/C, with lower onset potential for ethanol electrooxidation and notably improved peak current densities. Thus the presence of Ni and Co heteroatom seems to promote C–C bond cleavage and facilitate the removal from the catalyst surface of adsorbed intermediates. These trends are satisfactorily confirmed by testing in a direct ethanol fuel cell (DEFC), since trimetallic PtSnNi/C and PtSnCo/C anode catalysts have significantly higher overall performance and peak power density than Pt/C, PtSn/C or other trimetallic catalyst compositions PtSnRh/C or PtSnPd/C. Furthermore, the presence of Ni or Co helps to improve the weak stability of PtSn/C by providing a stronger Pt–carbon support interaction. XPS results revealed that the surface Pt/Sn atomic ratio of PtSnNi/C catalyst only slightly decreased even after 12 h at 500 mV. On the other hand, a higher concentration of oxide species appeared on the treated PtSn/C surface as a result of a high degradation of carbon support.     

Steam reforming of liquefied petroleum gas using catalysts supported on ceria-silica

Hydrogen production from steam reforming of liquefied petroleum gas (SR-LPG) process was studied over nickel, platinum, rhodium, and ruthenium-based catalysts supported on CeO₂–SiO₂ (CS). BET surface area, X-ray diffraction (XRD), temperature programmed reduction (TPR) and X-ray absorption near edge spectroscopy (XANES) techniques were used to characterize the samples. The catalytic activity and stability of the samples during SR-LPG were measured at 400 °C and 600 °C, respectively. XRD data were used to estimate the average crystallite size of ceria, which was small in all samples. For Pt and Rh containing samples, no diffraction peaks related to the metals were identified, which suggests high dispersion of these metals on the support. TPR and XANES experimental results showed that the addition of metals promoted the reduction of ceria. The order of catalyst activity for during SR-LPG at 400 °C was: Rh/CS » Pt/CS > Ru/CS » Ni/CS. Pt/CS and Rh/CS samples exhibited lower deactivation than nickel and ruthenium catalysts for SR-LPG at 600 °C during 24 h. Catalysts deactivation was mainly due to carbon deposition. In situ XRD data collected during SR-LPG at 600 °C revealed small increases in the mean particle sizes of Ni(0) and Ru (0), which could be pointed out as an additional cause for faster deactivation of the Ru/CS and Ni/CS catalysts.     

Glassy carbon electrode modified by Pd–Cu bimetallic nano-dendrites film decorated on the reduced graphene oxide using galvanic replacement as a low-cost anode in methanol fuel cells

Glassy carbon electrode (GCE) modified by reduced graphene oxide Cu–Pd nano-dendrimer (Pd-CuNDs-RGO/GCE) was prepared using electro-deposition and spontaneous displacement methods. Graphene oxide was put on the surface of GCE by drop-casting, then a thin film of reduced graphene oxide (RGO) was formed by electro-reduction at ?0.9 V. The copper nano-dendrimers (CuNDs) were electro-plated on RGO/GCE surface. Finally, Pd-CuNDs-RGO/GCE was prepared by the spontaneous replacement of CuNDs with palladium nanoparticles (PdNPs) in a dilute solution of palladium. The electrode surface was characterized using field-emission scanning electron microscopy (FESEM), X-ray energy diffraction (EDX) spectroscopy, and electrochemical techniques. The electrochemical behavior of the modified electrode in the oxidation of alkaline solution of methanol was investigated. The experimental conditions affecting the performance of the modified electrode in the methanol oxidation were studied and optimized. Finally, the proposed electrode has the onset potential of ?0.5 V and the ratio of i_f/i_b equal to 2.2, which confirms the high catalytic activity. The electrode has appropriate stability and shows about 86% of initial activity after 100 times testing.     

Use of graphene-supported manganite nano-composites for methanol electrooxidation

Binary nano-composites of palladium and a metal (Fe or Cu) manganite on graphene nanosheets (GNS) have been prepared by a microwave-assisted polyol reduction method and investigated as electrocatalysts for the methanol oxidation reaction (MOR) in 1 M KOH at 25 °C. Structural and electrocatalytic surface characterizations of composites are carried out by X-ray diffraction, transmission electron microscopy, X-ray photoelectron microscopy, cyclic voltammetry and chronoamperometry. Results show that new composite catalysts, particularly 40 wt%Pd–x wt%FeMn₂O₄/GNS (where x = 5, 8, 10 & 15) are MOR active and that the activity is the greatest with the catalyst containing 8 wt% of the oxide. The composite, Pd–8 wt%FeMn₂O₄/GNS, exhibits much superior catalytic activity as well as stability compared to the base (Pd/GNS) electrode. The enhanced catalytic activity and stability of the Pd/GNS catalyst in presence of the oxide can be ascribed to increased population of adsorbed OH⁻ ions/OH radicals at the electrode surface.     

Crystalline nickel boride nanoparticle agglomerates for enhanced electrocatalytic methanol oxidation

In this paper, crystalline Ni₃B nanoparticle agglomerates have been successfully prepared via dry-powder annealing of the solution-produced amorphous nickel boride. The electron microscopy (EM) images indicate that the Ni₃B nanomaterial is composed of numerous nano-sized particles with a diameter ranging from 100 to 200 nm. The electrocatalytic characteristics of nickel boride in an alkaline medium were observed by cyclic voltammetry (CV) and chronoamperomerty (CA). Compared to the amorphous nickel boride/Ni foam (ANB/NF), the crystalline Ni₃B/Ni foam (CNB/NF) electrode exhibits a higher catalytic performance with low initial oxidation potential of 0.35 V and a high anodic oxidation current density of 62 A g⁻¹ at 0.55 V in a 6 M KOH solution with 0.5 M methanol. And the CNB/NF electrode shows good long-term cycling stability and the catalytic current of methanol retains 87% of the initial value after 1000 time cycles. The CNB/NF electrode should be a promising candidate for alkaline direct methanol fuel cells (DMFCs).     

Enhanced electrocatalytic performance for methanol oxidation of a novel Pt-dispersed poly(3,4-ethylenedioxythiophene)–poly(styrene sulfonic acid) electrode

A new catalyst electrode was prepared in which Pt particles were homogeneously distributed into a poly(3,4-ethylenedioxythiophene)–poly(styrene sulfonic acid) (PEDOT–PSS) matrix. Catalytic activity and stability for the oxidation of methanol were studied by using cyclic voltammetry and chronoamperometry. For comparative purposes, bulk Pt and PEDOT–PSS based electrodes were fabricated and tested. Enhanced electrocatalytic activity toward the oxidation of methanol was noticed when Pt particles were embedded into the PEDOT–PSS matrix. A high catalytic current for methanol oxidation (2.51 mA cm⁻²) was found for the PEDOT–PSS–Pt electrode in comparison to bulk Pt electrode (0.45 mA cm⁻²) at +0.6 V (versus Ag/AgCl). The enhanced electrocatalytic activity might be due to the dispersion of Pt particles into the PEDOT–PSS matrix and the synergistic effects between the dispersed Pt particles and the PEDOT–PSS matrix. The morphology and crystalline behavior of PEDOT–PSS–Pt and simple ITO/Pt films were determined by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) and correlated with the enhanced electrocatalytic activity for the Pt-dispersed PEDOT–PSS electrode.     

Pd modified Ni nanowire as an efficient electro-catalyst for alcohol oxidation reaction

Developing highly efficient and economically viable electro-catalyst is very crucial research topic nowadays for achieving affordable direct alcohol fuel cells. Nano-structural architecture plays a crucial role in the catalytic activity. Herein we are reporting, a cost effective one-dimensional (1D) nano structured electro-catalyst for improved methanol oxidation reaction. Pd modified Ni nanowire catalyst towards methanol electro oxidation were prepared by a simple galvanic replacement reaction. Exclusive nano-wire morphology achieved through a wet chemical reduction method without employing any capping agents or surfactants. Pd modified Ni nano-wires exhibited a supreme catalytic activity and durability towards methanol electro-oxidation. The distinctive 1D morphology and strong metal support interaction (SMSI) between Pd and NiO along with the bifunctional effects of Pd and Ni attributed to the enhanced catalytic activity. The amount of precious Pd metal was reduced by 90 wt% with enhanced catalytic efficiency. Ethanol electro-oxidation study showed an improved catalytic activity with mass activity of 1479.79 mA/mg _Pd.     

Evaluation of sodium dodecyl sulfate effect on electrocatalytic properties of poly (4-aminoacetanilide)/nickel modified carbon paste electrode as an efficient electrode toward oxidation of ethylene glycol

Poly (p-aminoacetanilide) (PPAA) was prepared by oxidation of PAA in acidic aqueous solution in the presence of sodium dodecyl sulfate (SDS) at the surface of carbon paste electrode (CPE). Then Ni (II) ions were incorporated to the polymer by immersion of the modified electrode in a 0.1 M Ni (II) ions solution. The electrochemical behavior of this modified electrode (Ni/SDS-PPAA/CPE) was investigated by using cyclic voltammetry and chronoamperometry techniques. The experimental results exhibited the stable redox behavior of the Ni (III)/Ni (II) couple immobilized at the polymeric electrode. This polymeric modified electrode has a very good activity toward the ethylene glycol (EG) electrooxidation in a 0.1 M NaOH solution. By comparison of the different responses to EG oxidation using electrodes Ni/SDS-PPAA/CPE, Ni/PPAA/CPE and Ni/CPE, we observed that Ni/SDS-PPAA/CPE is a more effective catalyst for the electrooxidation of ethylene glycol. The anodic peak current of EG increases with increasing ethylene glycol concentration up to 0.08 M. A diffusion-controlled process at low EG concentrations and a kinetic-controlled process at high EG concentrations are predominant. Finally, the catalytic rate constant (k) for the ethylene glycol oxidation reaction was calculated 1.1 × 10⁴ cm³ mol⁻¹ s⁻¹ by using a chronoamperometric technique.     

Electrocatalytic activity of binary and ternary composite films of Pd,MWCNT and Ni,Part II: Methanol electrooxidation in 1 M KOH

Binary and ternary composite films of Pd, multiwalled carbon nanotubes (MWCNTs) and Ni have been obtained on glassy carbon electrodes and investigated for electrocatalysis of methanol oxidation in 1 M KOH. It is observed that small addition (1–5%) of MWCNTs to Pd increases the apparent electrocatalytic activity of the electrode considerably, the magnitude of enhancement, however, being the greatest (5–8 times) with 1% MWCNT. 1% Ni introduction to the active Pd–1% MWCNT electrode increased the apparent electrocatalytic activity by 1.4–1.7 times further. Among the electrodes investigated, the Pd–1% MWCNT–1% Ni composite electrode has the greatest apparent electrocatalytic activity. The enhanced electrocatalytic activity of the electrodes is ascribed to their improved geometrical as well as electronic properties.     

Remarkable electrocatalytic activity of Ni-nanoparticles on MOF-derived ZrO2-porous carbon/reduced graphene oxide towards methanol oxidation

In the present work, a porous carbonaceous platform containing zirconium oxide was used for spreading Ni nanoparticles, and applied to methanol oxidation. The platform was obtained by calcination of a metal-organic framework (MOF) attached to graphene oxide. Nickel nanoparticles were then deposited on the nanocomposite by chemical reduction from a Ni²⁺ solution. The obtained electrocatalyst was characterized by different methods. An excellent electrocatalytic behavior was observed towards methanol oxidation in alkaline medium (j ~ 240 mA cm^?2 or ~ 626 mA mg^?1 in 1.0 M methanol). The results of methanol oxidation by various electrochemical studies (cyclic voltammetry, electrochemical impedance spectroscopy, chronoamperometry and chronopotentiometry) revealed the effective synergy between reduced graphene oxide, porous carbon material, ZrO₂ metal oxide and Ni nanoparticles. Good durability and stability of the proposed electrocatalyst and significantly increased current density of methanol oxidation suggest it as a potential alternative for Pt-based electrocatalysts in direct methanol fuel cells.     

Preparation of PEDOT-modified double-layered hollow carbon spheres as Pt catalyst support for methanol oxidation

In this paper, Pt nanoparticles (Pt NPs) deposited hybrid carbon support is prepared by modifying double-layered hollow carbon spheres（DLHCs）with poly(3,4-ethylenedioxythiophene) (PEDOT) and used as anode catalyst of methanol oxidation. The structure of nanocomposites is characterized by SEM, TEM, FT-IR, XRD and XPS, confirming the greatly enhanced synergistic effect between the PEDOT and DLHCs, and illustrating the uniform distribution of Pt NPs on the PEDOT/DLHCs composite surface with a small particle size (~2.63 nm). Cyclic voltammetry, chronoamperometry and impedance spectroscopy applied to determine the electrocatalytic activity of catalysts, it is found that the synthesized PEDOT/DLHCs/Pt possesses excellent characteristics such as large electrochemically active surface area and high mass activity of 59.45 m² g⁻¹ and 807 mA mg⁻¹ in 0.5 M H₂SO₄ containing 1 M methanol solution, which is almost 1.24 and 2.8 times greater than those of commercial Pt/C, and the catalyst exhibits superior stability after 500 durability cycles. The enhanced electrocatalytic behavior can be ascribed to the excellent electronic conductivity of PEDOT-modified DLHCs and the strong binding of PEDOT/DLHCs to Pt NPs, suggesting that the PEDOT/DLHCs/Pt is a promising electrocatalyst for direct methanol fuel cell.     

Improved methanol electro-oxidation reaction on PdRh-PVP/C electrodes

Here we report on the organometallic synthesis of polyvinylpyrrolidone (PVP)-stabilized palladium-rhodium nanostructures that display high electrochemical properties when used as carbon-supported electrodes (Pd_xRh_1-x-PVP/C) for methanol oxidation reaction (MOR). These nanostructures were synthesized by hydrogenation of the tris(dibenzylideneacetone)dipalladium(0) (Pd₂(dba)₃) and tris(allyl) rhodium (Rh(η³-C₃H₅)₃) complexes, in tetrahydrofuran (THF) under mild reaction conditions (room temperature and 3 bar H₂) and in the presence of PVP as stabilizer. The influence of methanol concentration (0.5, 1.0 and 2.0 M) as well as different scan rates (5–100 mV s^?1) was evaluated to determine changes in the stability and catalytic activity. The organometallic approach and the use of PVP for the preparation of PdRh electrode materials promoted the formation of highly dispersed nanostructures, that led to a remarkably enhanced methanol electro-oxidation in alkaline medium. This high catalytic behavior can reasonably arise from a synergistic effect between Pd and Rh metals as, under the applied conditions, Rh is expected to enhance the Pd ability to oxidize methanol to CO₂ (oxophilic character) as well as the catalyst stability. From all the evaluated electrode materials, Pd₈Rh₂-PVP/C electrode showed the highest mass activity at high methanol concentration (2.0 M) and low scan rate (10 mV s^?1). This catalyst showed a performance up to 26 times higher than that of Pd-PVP/C and interestingly an electroactivity superior to that of previously reported PdRh catalysts.