Electrocatalysts For Methanol Oxidation Reaction Research Articles

NiSe integrated with polymerized reduced carbon sheet: As an effective electrocatalyst for methanol oxidation reaction

A low-energy approach was used to create ternary composites of hollow tubular Poly-N-methyl pyrrole (P-NMPy) and NiSe nanoparticles decorated onreduced graphene oxide (RGO). On the surface of RGO, P-NMPy, and NiSe nanoparticles were uniformly disseminated. The RGO/NiSe@P-NMPy (RNP) polymer nanocomposite was made utilizing a straightforward chemical oxidative process. The RGO/NiSe@P-NMPy nanocomposite was studied using FTIR spectroscopy, UV–visible, XRD, FE-SEM with EDAX, AFM, TEM and electrochemical investigations. The electrocatalytic activity of this polymer nanocomposite for the methanol oxidation reaction in alkaline environments was validated using cyclic voltammetry. The RGO/NiSe@P-NMPy electrocatalyst shows excellent electrocatalytic activity, lower oxidation potential (0.1 V), improved current density (127 mA/cm2), excellent stability and longevity (900 s) towards methanol oxidation reaction (MOR) in alkaline medium. It was observed RGO/NiSe@P-NMPy electrocatalyst, the ECSA value is 70.83 m2/g. This result clearly depicts that RGO/NiSe@P-NMPy electrocatalyst has more active sites for MOR reaction. According to the results, the P-NMPy introduction in RGO/Nickel Selenide structure can enhance the performance of methanol oxidation and increase the resistance to CO in comparison with monometallic catalysts.

The facile production of Fe2O3-biochar electrocatalyst for methanol oxidation reaction

In this study, the facile-green method was applied for the production of electroactive composite anode material. For this purpose, biochar was produced via pyrolysis of Pinus nigra (PN) sawdust in a stainless-steel reactor at 300, 400 and 500 °C with 10 °C/min heating rate. The Fe2O3 particles were fabricated via the green synthesis method. The Fe2O3-biochar electrocatalyst was operated on Ni foam electrode and the potential application as an anode for methanol fuel cell was investigated in an alkaline medium. Field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), Brunauer-Emmett-Teller analysis (BET), and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR/ATR) were used to characterize the morphology of the electrocatalyst samples. The electrochemical measurements of electrocatalyst samples were achieved via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV) and chronoamperometry (CA). The enlarged surface area of biochar enabled the formation of more electroactive sites for methanol electrooxidation and favorable structures of biochar could support to increased electrocatalytic activity of catalysts for methanol oxidation and produce favorable matrices for Fe2O3 loading. The obtained results demonstrate that the electrooxidation of methanol occurred at 0.36 V. The favorable structures of biochar acted as a support, enhancing the electrocatalytic activity of Fe2O3 for methanol oxidation. The electrocatalyst demonstrated remarkable activity with almost 4 A g−1 current density at 0.55 V. The Rct values were 0.73 Ω and 0.45 Ω at 0.55 V, for Ni foam and Ni foam/Fe2O3-biochar, respectively. Long-term measurements demonstrated that the Ni foam/Fe2O3-biochar catalysts was remarkably stable, with a 4 % difference in current before and after the CA analysis.

Binder-free cobalt molybdate nanoflakes grown on nickel foam as a hybrid supercapacitor and electrocatalyst for methanol oxidation reaction

In this work, Cobalt molybdate nanoflakes were grown on nickel foam which is used as an electrode for the supercapacitor and electrocatalyst for the methanol oxidation reaction. XRD, Raman, and XPS analysis further confirm the formation of CoMoO4. FESEM image shows that the CoMoO4 nanoflakes with a thickness of ∼91 nm and diameter of ∼1 µm were formed. In a three-electrode system, CoMoO4/NF exhibited a capacitance (capacity) of 359.8 F g−1 (215.88 Cg−1). CoMoO4/NF retained 73.8 % of capacitance after 9500 cycles with 89.4 % of coulombic efficiency. After a long cycle, the electrode undergoes XPS and FESEM analysis. From XPS, its major oxidation state was changed from 2+ to 3+ and Mo was leached out from the electrode. FESEM analysis showed that nanoflake size decreased to 53.34 nm from 91 nm. The aqueous hybrid supercapacitor (HSC) exhibited a capacitance of 86 F g−1 at 1 A g−1. Aqueous HSC exhibited an energy density of 17.5 Wh Kg−1 and a power density of 2970 W Kg−1. CoMoO4/NF showed good oxidation properties towards methanol to carbon dioxide. After the 1000 cycles, the forward oxidation peak shifted to −0.052 V from −0.00884 V vs Hg/HgO. After the 1000 cycles, a 46 % decrease in methanol oxidation current is observed.

RGO@Ni/NiO composite an effective electrocatalyst for methanol oxidation reaction in alkaline media

A composite comprised of reduced graphene oxide and nickel/nickel oxide (rGO@Ni/NiO) was synthesized and used as a modifier to fabricate a modified carbon paste electrode (CPE-rGO@Ni/NiO) for the methanol oxidation reaction (MOR) in alkaline medium. The fabricated CPE-rGO@Ni/NiO showed a pronounced electrocatalytic activity towards methanol oxidation at the potential of about 0.58 V vs. Ag|AgCl|KClsat. The effect of experimental parameters on the electrocatalytic activity of the prepared electrode towards MOR was explored in alkaline medium. The results of hydrodynamic chronoamperometry using the fabricated electrode showed enhanced stability towards MOR at the applied potential of 0.580 V for 11 h. The enhanced stability was attributed to the presence of rGO that not only provides a large conductive surface area with a high electron exchange property to accumulate Ni/NiO but also increases CO-tolerance to resist more towards intermediates.

Enlightening the performance-boosting effect of electroactivation approaches on the electrooxidation of methanol reaction in acidic media catalyzed by cobalt-tin bimetallic nanocatalysts

This research investigates the impact of electrochemical activation on cobalt-tin (Cox-Sn100-x) bimetallic nanocatalysts for the methanol oxidation reaction (MOR) in acidic conditions. Two electroactivation protocols, namely activation in a phosphate buffer (PB) solution and in-situ activation, using chronoamperometry, were developed. The electrochemical performance of the MOR electrocatalyst was evaluated through cyclic voltammetry analysis within a specific electrode potential range. Optimal activation conditions for the PB solution were achieved at a pH of 3.0 and an activation potential of −1.3 V (vs. Ag/AgCl), while the in-situ activation process showed the best results at an activation potential of −0.7 V (vs. Ag/AgCl). Both the in-situ and PB electroactivated Co65–Sn35 catalysts exhibited significant enhancements in MOR activity, with the in-situ activation resulting in a 10-fold increase and the PB activation leading to an 8.5-fold increase. The proposed mechanism for this substantial enhancement involves simultaneous hydrogen evolution and water electrolysis during the electroactivation treatments of the Co65–Sn35 electrocatalyst. In fact, the formation of OHads species during the electroactivation treatment could provide a fraction of OHads which was essential for the MOR. These findings might present opportunities for the engineering and design of bimetallic noble metal-free nanocatalysts for efficient utilization in high-performance acidic direct methanol fuel cells (DMFCs).

Atomically Dispersed CrOX on Pd Metallene for CO-Resistant Methanol Oxidation.

The effective design and construction of high-performance methanol oxidation reaction (MOR) electrocatalysts are significant for the development of direct methanol fuel cells. But the active sites of the MOR electrocatalysts are susceptible to being poisoned by CO, resulting in poor durability. Herein, we report an atomically dispersed CrOX species anchored on Pd metallene through bridging O atoms. This catalyst shows an outstanding MOR performance with 7 times higher mass activity and 100 mV lower CO electrooxidation potential than commercial Pd/C. The results of operando electrochemical Fourier transform infrared spectroscopy demonstrate the rapid removal of CO* on CrOX-Pd metallene. Theoretical calculations reveal that atomically dispersed CrOX can lower the adsorption energy of CO* on Pd sites and enhance that of OH* through the formation of a hydrogen bond, decreasing the formation energy of COOH*. This work provides a new strategy for improving MOR performance via atomically engineering oxide/metal interfaces.

Interfacial engineering of nickel selenide with CeO2 on N-doped carbon nanosheets for efficient methanol and urea electro-oxidation

The design of low cost, high efficiency electrocatalysts for methanol oxidation reactions (MOR) and urea oxidation reactions (UOR) is a pressing need to address the energy crisis and water pollution. In the present work, we developed Cerium dioxide (CeO2) and nickel selenide (Ni0.85Se) nanoparticles integrated into three-dimensional N-doped carbon nanosheets to be used as efficient and stable bifunctional electrocatalysts for MOR and UOR. By optimizing the selenization temperature, the CeO2-modified Ni0.85Se obtained at selenization temperature of 550 °C (CeO2-Ni0.85Se-550-NC) has the best MOR and UOR electrochemical performance. The CeO2-Ni0.85Se-550-NC potential only requires 1.309 V (MOR) and 1.294 V (UOR) to reach 10 mA cm−2, respectively. The DFT study reveals that CeO2-Ni0.85Se-550-NC has the best reaction path with the synergistic effect between CeO2 and Ni0.85Se. The outstanding catalytic performance of CeO2-Ni0.85Se-550-NC may be due to the cointeraction between CeO2 and Ni0.85Se, allowing more defects that function as catalytic sites while promoting fast electron transfer in the N-doped carbon substrate.

Formation mechanism of macroporous Cu/CuSe and its application as electrocatalyst for methanol oxidation reaction

Single-step solvothermal method is used to prepare Cu/CuSe as an electrocatalyst for methanol electro-oxidation reaction (MOR). 1,3-butan-diol is selected as a reaction medium, whose viscosity and complex formation with Cu(II) ions dictate the catalyst morphology. The catalyst has a macroporous structure, which is composed of nanoballs with a high purity, crystallinity, and uniform morphology. The electrocatalyst is excellent for MOR, as it delivers current density of 37.28 mA/mg at potential of 0.6 V (vs Ag/AgCl) in the electrolyte of 1 M KOH and 0.75 M methanol at a 50 mV/s scan rate under conditions of cyclic voltammetry. The catalyst also shows good stability for 3600 s with negligible charge transfer resistance and high electrochemical active surface area (ECSA) value of 0.100 mF/cm2.

Facile synthesis of PEG-glycerol coated bimetallic FePt nanoparticle as highly efficient electrocatalyst for methanol oxidation

Direct methanol fuel cell (DMFC) has shown excellent growth as an alternative candidate for energy sources to substitute fossil fuels. However, developing cost-effective and highly durable catalysts with a facile synthesis method is still challenging. In this prospect, a facile strategy is used for the preparation of hydrophilic Fe-Pt nanoparticle catalyst via a polyethylene glycol-glycerol route to utilize the advantages of nanostructured surfaces. The synthesized electrocatalysts are characterized by XRD, XPS, TEM, EDS and FTIR to confirm their structure, morphology, composition, and surface functionalization. The performance of the catalysts towards methanol oxidation reaction (MOR) was investigated by cyclic voltammetry and chronoamperometry in both acidic and alkaline media. The Fe-Pt bimetallic catalyst exhibits better current density of 36.36 mA cm−2 in acidic medium than in alkali medium (12.52 mA cm−2). However, the high If/Ib ratio of 1.9 in alkali medium signifies better surface cleaning/regenerating capability of catalyst. Moreover, the catalyst possessed superior cyclic stability of ~ 80% in the alkaline electrolyte which is 1.6 times higher than in the acidic one. The better stability and poison tolerance capacity of catalyst in alkaline media is attributed to the OH− ions provided by the electrolyte which interact with the metal species to form M-(OH)x and reversibly release OH− and regenerate metal surface for further oxidation reactions. But synergism provided by Fe and Pt gives better activity in acidic electrolyte as Pt is favourable catalyst for dehydrogenation of methanol in acidic medium. This study will be useful for designing anodic electrocatalysts for MOR.

Formicary-like PtBi1.5Ni0.2Co0.2Cu0.2 high-entropy alloy aerogels as an efficient and stable electrocatalyst for methanol oxidation reaction

High-entropy alloy aerogels (HEAAs) have become promising electrochemical catalysts because of the advantageous combination of high-entropy alloys and aerogel structure. However, how to fabricate 3D porous high-entropy alloys accurately is still a great challenge due to their inherent thermodynamic instability and differences in reduction potentials of metal ions. Herein, PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs have been synthesized by combining co-reduction method and freeze-drying technology. The resulting PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs have the structural and morphological benefits of both high-entropy alloys and aerogels. Both XPS and DFT results confirm that the d-band center of PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs shifts to lower binding energy compared to Pt/C, indicating the effective regulation of electronic structure on the surface of PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs. As a demonstration in the methanol oxidation reaction (MOR), a mass activity of 4.19 A mgPt−1 and long-term stability (>0.33 A mgPt−1 after 10 cycles of 3600 s stability test) can be obtained on the PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs, outperforming binary Pt-based alloys and commercial Pt/C. The CO adsorption strength of PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs is more weaker than that of PtBi1.5 alloys and Pt/C, which proves the enhanced CO tolerance. The results pave the way for fabricating the hybrids of high-entropy alloys and aerogels with superior activity and stability.

Constructing a CrCoNi medium entropy alloy coordinated Pt ultrathin film as durable electrocatalysts for methanol oxidation reaction

As high-efficiency anode methanol oxidation catalysts, platinum-based materials have always occupied a dominant place since the inception of direct methanol fuel cells (DMFCs). However, because of the strong adsorption of intermediates, Pt-active centers are easily poisoned and induce serious activity loss. Here, we investigate the same commonality of the oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) mechanism in Pt/CrCoNi complex catalysts and establish a relationship between them to help screen appropriate synergistic materials and reduce activity loss. With this strategy, the OER activity of Pt/CrCoNi is modified via temperature and oxygen pressure control, and the OER overpotential and MOR durability show a positive correlation. The MOR performance of the final optimized Pt/CrCoNi (7.5–225 Torr oxygen pressure and 400 °C annealing, OA) film reaches an advanced level in the Pt-based MOR catalysts and shows a mass activity of 3785 A gPt-1, as well as a good durability of 50000 s in the alkaline solution.

Insights on the Roles of Nitrogen Configuration in Enhancing the Performance of Electrocatalytic Methanol Oxidation over Pt Nanoparticles.

Stabilization of the Pt in N-doped carbon materials is an effective method to improve the performance of electrocatalytic methanol oxidation reaction (MOR). Nevertheless, the roles of different N configurations (pyridinic N, pyrrolic N, and graphitic N) toward the electrochemical performance of Pt-based catalysts remain unclear. Herein, Density Functional Theory calculations are adopted to elucidate the synergistic promotion of MOR by different N-configurations with Pt nanoparticles (NPs). Guided by the theoretical study, a series of MOR electrocatalysts with different ratios of pyridinic N and pyrrolic N (denoted as Pt/N-CNT-X (500, 600, 700, 800, and 900)) are designed and synthesized. Surprisingly, the electrocatalytic activity of Pt/N-CNT-600 with a suitable ratio of pyrrolic-N and pyridinic-N for MOR reaches 2394.7mAmg-1 Pt and 5515.8mAmg-1 Pt in acidic and alkaline media, respectively, which are superior to the Pt/CNTs, commercial Pt/C, and the ever-reported Pt-based electrocatalysts. The strong metal-support interaction induced by the N-doping is the crucial reason for the superior electrocatalytic performance. More importantly, the ability of pyrrolic-N and pyridinic-N in promoting the adsorption and oxidation of CH3 OH and the oxidation of CO* is substantiated for the first time in methanol oxidation. This work provides new insights on the design of efficient electrocatalysts for MOR.

Simple, Green and Low-Cost Ni Nanoparticles/Tissue-Derived Nitrogen-Doped Porous Carbon Nanocomposites as an Efficient Electrocatalyst for Methanol Oxidation Reaction

Simple, Green and Low-Cost Ni Nanoparticles/Tissue-Derived Nitrogen-Doped Porous Carbon Nanocomposites as an Efficient Electrocatalyst for Methanol Oxidation Reaction

Hierarchically heterostructured Pt/CrN–TiN derived from metal organic frameworks as an efficient electrocatalyst for methanol oxidation reaction

Exploiting cost-effective and highly efficient electrocatalysts toward methanol oxidation reaction (MOR) is meaningful but challenging. Metal-organic framework (MOF)-based derivatives have attracted much attention of the community in various research fields. Herein, a novel metal-organic framework derived three dimensional (3D) heterostructure (Pt/CrN–TiN) has been synthesized as an efficient MOR electrocatalyst through interfacial engineering. Benefiting from the unique 3D penetrating structure and the abundant heterogeneous interfaces, the Pt/CrN–TiN heterostructure exposed maximum active sites, open diffusion channels, and accelerated electron transfer at heterogeneous interfaces, thus modulating adsorption/desorption behavior of targeted reactants/intermediates and eventually facilitating the MOR kinetics. Impressively, the designed Pt/CrN–TiN catalyst performed high catalytic activity toward methanol oxidation reaction (1.14 A mgpt−1) compared to that of Pt/CrN (0.18 A mgpt−1), Pt/TiN (0.64 A mgpt−1) and Pt/C (0.44 A mgpt−1), respectively. Density functional theory (DFT) calculations reveal that the existing heterointerfaces optimize the free energy of intermediates during MOR, accelerating the reaction kinetics. We believe that the current work provides new insight and useful guidance for fabricating advanced electrocatalysts.

Toward Electrocatalytic Methanol Oxidation Reaction: Longstanding Debates and Emerging Catalysts.

The study of direct methanol fuel cells (DMFCs) has lasted around 70 years, since the first investigation in the early 1950s. Though enormous effort has been devoted in this field, it is still far from commercialization. The methanol oxidation reaction (MOR), as a semi-reaction of DMFCs, is the bottleneck reaction that restricts the overall performance of DMFCs. To date, there has beenintense debate on the complex six-electron reaction, but barely any reviews have systematically discussed this topic. To this end, the controversies and progress regarding the electrocatalytic mechanisms, performance evaluations as well as the design science toward MOR electrocatalysts are summarized. This review also provides a comprehensive introduction on the recent development of emerging MOR electrocatalysts with a focus on the innovation of the alloy, core-shell structure, heterostructure, and single-atom catalysts. Finally, perspectives on the future outlook toward study of the mechanisms and design of electrocatalysts are provided.

High-performance Mo2C/MWCNT electrocatalyst for MOR: Comparison with MoO2/MWCNT and MoO3/MWCNT

Methanol oxidation reaction (MOR) in the direct methanol fuel cells involves six electron transfer processes, and noble metal based catalysts such as Pt and Pd are still recognized as efficient catalysts for MOR. It is generally accepted that the reaction is mainly related to the d states of precious metal-based catalysts. Transition metal carbides and noble metals exhibit similar d band structure and catalytic properties, among which molybdenum carbide is an effective catalyst. However, molybdenum carbide-based catalysts have not been used in methanol electrooxidation reactions until the present moment, and we tried to use Mo2C/MWCNT for the MOR reaction. Compared with MoO2/MWCNT and MoO3/MWCNT, it is found that Mo2C/MWCNT shows the highest electrocatalytic activity, and the current density of Mo2C/MWCNT is 185 mA cm−2 in 1 M KOH+1 M CH3OH at 0.70 V (vs. Hg/HgO). The current density is about 2.2 times and 1.4 times higher than those of MoO2/MWCNT and MoO3/MWCNT catalysts, respectively, and the electrochemical impedance also decreases markedly. The current density retains 76.19% of the initial catalytic activity after 10 h at the Mo2C/MWCNT electrode, indicating that the catalyst has superior stability for MOR. The reaction pathway of MOR on Mo2C/MWCNT is as follows: CH3OH∗ → CH3O∗→ CH2O∗ → CH2OOH∗ → CH2OO∗ → CHOO∗ → CO2∗. The result not only expands the Mo2C application area, but also provides a new idea for the design of the MOR catalyst.

Enhancing methanol oxidation reaction with platinum–ruthenium embedded MXene: Synthesis, characterization, and electrochemical properties

Methanol oxidation reaction (MOR) is the main reaction that takes place in an anodic electrode of a direct methanol fuel cell (DMFC), whichis a promising electrochemical energy conversion technology. This study presents a novel approach for enhancing the electrocatalytic activity of MOR performance using composite of MXene (Ti3C2Tx) with Pt and Ru bimetal. The aimed of this study is to investigates the optimum electrocatalyst loading for PtRu/Ti3C2Tx to improve and stand out the potential of electrocatalysts in the MOR catalytic activity. The study also provides detailed physical characterizations and electrochemical measurements. The results show that the electrocatalyst loading of 0.40 mgcm−2 has the highest ECSA value and better reaction activity compared to other loadings. The electrocatalytic activity, CO tolerance, and stability of the electrocatalyst also show the better result for this loading. The comparative study with previous research shows that the PtRu/Ti3C2Tx electrocatalyst exhibits the highest catalytic activity, which is 5.13 times better than that of the previous study on the Pt/C electrocatalyst. Thus, the novel combination of MXene structure and PtRu indicates a promising electrocatalyst for MOR.

Coordination-driven self-assembly of MOF-based heterostructures for electrocatalytic methanol oxidation

Direct methanol fuel cells (DMFCs) are considered one of the most promising energy conversion devices due to their environmentally friendly and high-energy density features. However, the sluggish anode kinetics of the methanol oxidation reaction (MOR) acts as a bottleneck in the DMFCs system. Herein, a series of MOF-based heterogeneous electrocatalysts (NiWO4/MOF-74-x, Ni3V2O8/MOF-74-x) is constructed via a coordination-driven self-assembly strategy to enhance the catalytic property of the MOR. The heterogeneous interface between MOF-74 and Ni compounds is built by the Ni–O coordination interaction, which provides fast charge transfer and mass diffusion efficiency. Therefore, the optimal catalyst NiWO4/MOF-74 (3) exhibits excellent MOR activity and operation durability with a peak current density of 28.58 ​mA·cm-2. This work is expected to inspire the design of more efficient MOF-based heterogeneous electrocatalysts for MOR and other energy conversion applications.

Understanding Trends in Electrochemical Methanol Oxidation Reaction Activity on a Single Transition-Metal Atom Embedded in N-Coordinated Graphene Catalysts

The lack of efficient catalysts and research on the mechanism for the methanol oxidation reaction (MOR) impedes the development of direct methanol fuel cells. In this work, based on density functional theory calculations, we systematically investigated the activity trends of electrochemical MOR on a single transition-metal atom embedded in N-coordinated graphene (M@N4C). By calculating the free energy diagrams of MOR on M@N4C, Co@N4C was screened out to be the most effective MOR catalyst with a low limiting potential of 0.41 V due to the unique charge transfers and electronic structures. Importantly, one- and two-dimensional volcano relationships in MOR on M@N4C catalysts are established based on the d-band center and the Gibbs free energy of and ΔG*CO, respectively. In one word, this work provides theoretical guides toward the improved activity of MOR on M@N4C and hints for the design of active and efficient MOR electrocatalysts.

Controlled synthesis of Pd–Ag nanowire networks with high-density defects as highly efficient electrocatalysts for methanol oxidation reaction

Pd–Ag bimetallic catalysts containing different molar ratios of Pd/Ag (30/70, 50/50, and 70/30) were prepared using a facile visible-light-assisted liquid-phase method. The samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, selected-area electron diffraction, and inductively coupled plasma optical emission spectroscopy. Cyclic voltammetry and chronoamperometry measurements were used to evaluate their electrocatalytic properties toward the methanol oxidation reaction (MOR) in alkaline media. The alloyed Pd50Ag50 nanowire network with the optimized molar ratio, which had abundant defects (grain boundaries, lattice dislocations, lattice expansion, and distortion), provided more active sites for the MOR under alkaline conditions. The onset potential of the MOR on the Pd50Ag50-loaded glassy carbon electrode (GCE) was more negative than those on the Pd30Ag70, Pd70Ag30, and pure Pd electrodes. The Pd50Ag50 catalyst showed the best catalytic activity (2853 mA mgPd−1/6.85 mA cmPd−2) compared with those of the pure Pd catalyst (320 mA mgPd−1/2.68 mA cmPd−2) and other samples. This sample also exhibited a high tolerance (ib/if = 0.19) to the poisoning species and long stability (only lost 7.64 % after 500 cycles). The alloyed Pd50Ag50 network is a promising catalyst for the MOR. This work may be extended to construct advanced Pd–M (M = other metals) catalysts for fuel cell applications by surface defect engineering.