Carbon Black Support Research Articles

Carbon supported Ag nanoparticles with different particle size as cathode catalysts for anion exchange membrane direct glycerol fuel cells

The effect of Ag particle size on oxygen reduction reaction (ORR) at the cathode was investigated in anion exchange membrane direct glycerol fuel cells (AEM-DGFC) with oxygen as an oxidant. At the anode, high purity glycerol (99.8 wt%) or crude glycerol (88 wt%, from soybean biodiesel) was used as fuel, and commercial Pt/C served as the anode catalyst. A solution phase-based nanocapsule synthesis method was successfully developed to prepare the non-precious Ag/C cathode catalyst, with LiBEt3H as a reducing agent. XRD and TEM characterizations show that as-synthesized Ag nanoparticles (NP) with a size of 2–9 nm are well dispersed on the Vulcan XC-72 carbon black support. Commercial Ag nanoparticles with a size of 20–40 nm were also supported on carbon black as a control sample. The results show that higher peak power density was obtained in AEM-DGFC employing an Ag-NP catalyst with smaller particle size: nanocapsule made Ag-NP > commercial Ag-NP (Alfa Aesar, 99.9%). With the nanocapsule Ag-NP cathode catalyst, the peak power density and open circuit voltage (OCV) of AEM-DGFC with high-purity glycerol at 80 °C are 86 mW cm−2 and 0.73 V, respectively. These are much higher than 45 mW cm−2 and 0.68 V for the AEM-DGFC with the commercial Ag/C cathode catalyst, which can be attributed to the enhanced kinetics and reduced internal resistance. Directly fed with crude glycerol, the AEM-DGFC with the nanocapsule Ag-NP cathode catalyst shows an encouraging peak power density of 66 mW cm−2, which shows great potential of direct use of biodiesel waste fuel for electricity generation.

Electrochemical Properties and Durability of Electrocatalysts Supported on SnO 2

For polymer electrolyte fuel cells (PEFCs), carbon corrosion, leading to lower activities of catalysts under cathode conditions, is one of the important technological issues to be solved. We have been developing SnO2 and Nb-SnO2 as alternative support materials. In this study, the oxygen reduction reaction (ORR) activity and the durability of Pt/SnO2 and Pt/Sn0.98Nb0.02O2 against voltage cycling between 1.0 and 1.5 VRHE are quantitatively investigated. Longer ORR durability was verified, compared to the standard catalyst, Pt/Vulcan. Furthermore, we have found that the degradation mechanism of ORR is probably different between carbon black and SnO2-based supports. In the case of SnO2-based catalysts, degradation arose mainly from the loss of electrochemical surface area (ECSA), while other factors were also involved for Pt/Vulcan. Consequently, SnO2 is a promising candidate electrocatalyst support material to solve carbon corrosion problems of PEFCs.

Bimodal Pt Synthesized on Heat Treated Carbon Black Support in Arc Plasma Process

In general, furnace carbon black is used for support material thank to large specific surface area, good electrical conductivity, and chemical inertness. However, carbon corrosion degrades catalyst performance by electrically isolating detached Pt. Also, surface oxide species makes the catalyst be hydrophilic [1]. In this regard, Vulcan XC-72 carbon black was heat treated at 1,000°C, 1,100°C, and 1,200°C for 4 hours in a reducing environment in order to change crystallinity and surface properties. As the heat treatment temperature is increased, specific surface area by BET analysis is not markedly changed. However, changes of crystallinity from X-ray diffractometry, Raman spectroscopy, and high resolution transmission electron microscopy are notable. After that, Pt/C nano-catalysts are synthesized by arc plasma deposition process. Conclusively, Pt morphology can be tailored by carbon heat- treatment in the arc plasma synthesis and durable Pt/C is synthesized without post-synthesis heat treatment in liquid base synthesis.

A novel nitrogen-containing electrocatalyst for oxygen reduction reaction from blood protein pyrolysis

We report a new strategy to design carbon-based electrocatalysts containing nitrogen through the co-pyrolysis of blood protein and carbon black support. The results show that the nitrogen in electrocatalysts is primarily in the form of pyridinic- and pyrrolic-type nitrogen species. High-temperature pyrolysis processes can transfer a significant amount of pyridinic-N to pyrrolic-N. The electrocatalyst containing a higher amount of the pyrrolic-N configuration exhibits better electrocatalytic activity towards oxygen reduction reaction in terms of onset potential, half-wave potential, and limited current density. It is suggested that the pyrrolic-N configuration may be the electrocatalytically active site and may be responsible for the enhanced ORR performance in alkaline media. The carbon black support also plays an important role in the pyrolysis process, improving the ORR catalytic activity.

Investigating the activity enhancement on PtxCo1−x alloys induced by a combined strain and ligand effect

Due to their high activity for the oxygen reduction reaction (ORR), Pt based alloys are of considerable interest as catalysts for polymer electrolyte fuel cells (PEMFC). We present two synthesis protocols that give PtxCo1−x alloy nanoparticles (NPs) supported on a commercial carbon black support (Ketjen black EC300J) with controlled particle size, Co content and particle distribution for oxygen reduction reaction (ORR). The as prepared catalysts samples can be pre-leached in acid solution to obtain skeleton NPs and heat-treated in a reducing atmosphere to promote alloying as well as to reduce the number of low coordinated surface sites of the NPs. Without heat treatment, the catalysts exhibit an activity increase for the oxygen reduction reaction mainly due to a strain effect, whereas an improved performance due to a combined strain and ligand effect requires thermal treatment of the catalyst.

Preparation of Electrocatalysts for Polymer Electrolyte Fuel Cell Cathodes From Au-Pt Core-Shell Nanoparticles Synthesized by Simultaneous Aqueous-Phase Reduction

Electrocatalysts for polymer electrolyte fuel cell (PEFC) cathodes were prepared using Au-Pt core-shell nanoparticles. Polyvinylpyrrolidone (PVP)-protected core-shell nanoparticles were synthesized by simultaneous aqueous-phase reduction of Au and Pt, and they were deposited on carbon black support material. The catalyst powder was thermally processed in air to remove PVP, since the protecting polymers prevent nanoparticles from directly contacting the support material as well as reactant molecules. To avoid sintering during the thermal treatment, the effects of temperature and processing time on sintering were carefully examined. It was found that PVP was selectively oxidized and removed at 170 °C in air without notable damages to the other components of the catalyst. Stability of the core-shell catalyst in water was improved after the removal of PVP. The oxidation state of the Pt shell was found to be very close to zero. The thus-prepared Au-Pt core-shell catalyst for a PEFC cathode exhibited mass activity that was 20% higher than that of pure Pt catalyst.

Preparation and characterisation of Ti oxide based catalyst supports for low temperature fuel cells

Bare and doped Ti-oxides were prepared by using various synthesis routes and investigated in terms of structure, morphology and electrochemical properties for application as catalyst supports in low temperature fuel cells. A crystalline Anatase phase was obtained for most of the doped and undoped Ti-oxide supports after an air treatment in a range 300°–600 °C. Rutile structure was observed for treatments at higher temperatures. BET surface area varied as a function of the preparation route, the doping agent and the thermal treatment. BET surface area decreased passing from bare TiO2 to Ta-doped TiO2 and further decreased in the presence of Nb doping. A sulphite complex route allowed to achieve crystalline materials with crystallite domain sizes of about 3–4 nm upon thermal treatment at 400 °C. The corresponding BET surface area for TiO2 was around 250 m2/g whereas it decreased to 175 m2/g for the doped support. Electrochemical oxidation tests at 1.4 V RHE showed that oxide supports were significantly more stable in terms of electrochemical corrosion than conventional carbon black supports used in fuel cells. This comparison was extended to Ti-suboxides with Magneli phase obtained by high temperature reduction. The latter material appeared also very stable but characterised by low surface area (about one order of magnitude lower than bare TiO2) due to the high temperature treatment. Oxygen reduction reaction studies (ORR) showed that suitable performance can be achieved in the presence of a proper combination of electronic conductivity and dispersion for the oxide supported catalyst nanoparticles.

Electrogeneration of hydrogen peroxide in gas diffusion electrodes modified with tert-butyl-anthraquinone on carbon black support

Hydrogen peroxide (H2O2) is a versatile oxidizing agent that is synthesized commercially by the reduction of oxygen in organic medium. Electrochemical technology employing a modified gas diffusion electrode (MGDE) offers a viable alternative for the industrial-scale synthesis of the oxidant. Addition of 1% (w/w) of tert-butyl-anthraquinone (TBAQ) to carbon black deposited in the form of a microporous layer onto the disk of a rotating ring-disk electrode produced an increase in the ring current, which is directly related to H2O2 formation, and presented an efficiency of H2O2 generation of 89.6% compared with 76.6% for carbon black alone. No significant changes were detected in the number of electrons transferred in the presence of the catalyst suggesting an electrochemical/chemical mechanism for H2O2 formation. Analogous improvements in the generation of H2O2 were obtained with MGDEs comprising TBAQ on carbon black. The highest concentrations of H2O2 (301mgL−1) were produced at the fastest rate (5.9mgL−1min−1) with the lowest energy consumption (6.0kWhkg−1) when a potential of −1.0V vs SCE was applied to a MGDE containing 1.0% of TBAQ on carbon black. It is concluded that the application of MGDEs comprising TBAQ on carbon black support offers considerable advantages in the electrogeneration of H2O2.

Tuning the Location of Niobia/Carbon Composites in a Biphasic Reaction: Dehydration of d-Glucose to 5-Hydroxymethylfurfural

The conversion of glucose to 5-hydroxymethylfurfural (HMF) was studied in a biphasic system with niobia solid acid catalysts. We used carbon supported niobia since it shows improved hydrothermal stability. However, the carbon supported catalysts tend to be located in the organic phase due to their hydrophobic nature, while the reactant glucose is present in the aqueous phase. Therefore, we functionalized the carbon black support to increase the degree of hydrophilicity, allowing us to locate the catalyst either in the organic phase, in the aqueous phase or at the interface. The effect of the location of the niobia/carbon composites on the catalytic performance was investigated in the conversion of d-glucose to HMF in a biphasic system. It was found that the niobia catalyst located in the aqueous phase showed the highest d-glucose conversion (twofold greater than the others). We also compared the performance of catalysts obtained by deposition of niobia on functionalized carbon with a catalyst prepared by deposition precipitation-carbonization (DPC). The latter catalyst provides crystalline niobia particles while the other catalysts yield amorphous niobia. The crystalline niobia is more active for the acid catalyzed dehydration of isopropanol in the vapor phase. The DPC method provides a simple one pot synthesis to generate niobia particles embedded in a carbon support. .

Influence of Ink Composition on the Electrochemical Properties of Pt/C Electrocatalysts

Nanoparticle platinum on carbon black supports (Pt/high surface area carbon or Pt/HSC and Pt/Vulcan), widely used to benchmark novel electrocatalysts for proton exchange membrane fuel cells (PEMFCs), were characterized in rotating disk electrode (RDE) setups using multiple ink formulations. The oxygen reduction reaction (ORR) specific activity measured in 0.1 M HClO4 was higher by a factor of ~1.8 when Nafion ionomer was excluded from Pt/HSC inks/electrodes and substituted with trace amounts of a non-ionic surfactant for improved dispersiblity. Pt/Vulcan electrocatalysts did not exhibit this enhancement when Nafion was replaced with trace surfactant; however, eliminating both Nafion and the surfactant raised its specific and mass activity by a factor of ~1.8. The electrochemical areas for optimized inks/electrodes with and without Nafion were relatively unchanged at ~100 m2/g for Pt/HSC and ~65 m2/g for Pt/Vulcan. The higher measured activities have significant implications for established conventions regarding 'particle size effects'.

Carbon supported Ag nanoparticles as high performance cathode catalyst for H2/O2 anion exchange membrane fuel cell.

A solution phase-based nanocapsule method was successfully developed to synthesize non-platinum metal catalyst—carbon supported Ag nanoparticles (Ag/C). XRD patterns and TEM image show Ag nanoparticles with a small average size (5.4 nm) and narrow size distribution (2–9 nm) are uniformly dispersed on the carbon black Vulcan XC-72 support. The intrinsic activity and pathway of oxygen reduction reaction (ORR) on the Ag/C and commercial Pt/C were investigated using rotating ring disk electrode (RRDE) tests at room temperature. The results confirmed that the 4-electron pathway of ORR proceeds on small Ag nanoparticles, and showed comparable ORR activities on the self-prepared Ag/C and a commercial Pt/C. A single H2-O2 anion exchange membrane fuel cell (AEMFC) with the Ag/C cathode catalyst exhibited an open circuit potential of 0.98 V and a peak power density of 190 mW/cm2 at 80°C.

Investigation of the corrosion of carbon supports in polymer electrolyte fuel cells using simulated start-up/shutdown cycling

The corrosion of carbon black (CB) support materials for polymer electrolyte fuel cells was investigated by use of two standard accelerated testing protocols, square wave cycling (E=0.9–1.3V vs. RHE, holding 30s at each E) and triangular wave cycling (E=1.0–1.5V vs. RHE, at a scan rate of 0.5Vs−1) protocols, which were operated with H2 (anode) and N2 (cathode) atmospheres at 80°C and 100% RH. Severe decreases of the electrochemically active surface area (ECSA), mass activity (MA@0.85V) and cell performance resulting from the simulated start-up/shutdown cycling are ascribed to the detachment of Pt particles from the CB support due to carbon corrosion and structural collapse, as well as Ostwald ripening. First, the simulated start-up/shutdown cycling brings about the surface corrosion of the CB particles, and thereafter it transforms the crystalline carbon into amorphous carbon, which subsequently undergoes corrosion. This continual corrosion process of the CB support leads to a significant thickness reduction of the Pt/CB cathode catalyst layer and the severe detachment of Pt particles from the CB. On the CB particles, the slower square wave cycling brings about their overall corrosion, including the surface defects and anchoring centers where Pt particles are well attached and dispersed, whereas the faster triangular wave cycling brings about corrosion locally at more unstable surface defects on the CB particles. This is why the estimated cycle half-life N1/2 (at which ECSA is estimated to decrease to ca. 1/2 of the initial value) for the Pt/CB cathode catalyst was 10 times shorter with the square wave cycling compared to that with the triangular wave cycling. The effect of overall cycling time vs. cycle number is also discussed.

Nanostructured carbon-supported Pd electrocatalysts for ethanol oxidation: synthesis and characterization

The need to lower the construction cost of fuel cells calls for the development of non-Pt based electrocatalysts. Among others, Pd has emerged as a promising alternative to Pt for fuel cell catalysis. This research aims to investigate the synthesis and characterization of nanostructured Pd-based catalysts dispersed on carbon support as anode materials in direct ethanol fuel cells. For the preparation of the first Pd-based electrocatalyst, palladium nanoparticles (NPs) were synthesized via oleylamine (OAm)-mediated synthesis and precursor method with a mean particle size of 3.63 ± 0.59 nm as revealed by transmission electron microscopy (TEM). Carbon black was used as a supporting matrix for the OAm-capped Pd NPs. Thermal annealing and acetic acid washing were used to remove the OAm capping agent. To evaluate the electrocatalytic activity of the prepared electrocatalyst towards ethanol oxidation, cyclic voltammetry (CV) studies were performed using 1.0 M ethanol in basic medium. The CV data revealed the highest peak current density of 11.05 mA cm−2 for the acetic acid-washed Pd/C electrocatalyst. Meanwhile, the fabrication of the second Pd-based electrocatalyst was done by functionalization of the carbon black support using 3:1 (v/v) H2SO4:HNO3. The metal oxide, NiO, was deposited using precipitation method while polyol method was used for the deposition of Pd NPs. X-ray diffraction (XRD) analysis revealed that the estimated particle size of the synthesized catalysts was at around 9.0–15.0 nm. CV results demonstrated a 36.7% increase in the catalytic activity of Pd–NiO/C (functionalized) catalyst towards ethanol oxidation compared to the non-functionalized catalyst.

Tailoring Synthesis Conditions of Carbon Xerogels towards Their Utilization as Pt-Catalyst Supports for Oxygen Reduction Reaction (ORR)

Carbon xerogels characterized by different textural, structural and chemical properties were synthesized and used as supports for Pt catalysts for the application in polymer electrolyte fuel cells. Synthesis conditions were varied in order to synthesize carbon xerogels following the sol-gel method. These included the reactants ratio (precursor/formaldehyde), the catalyst concentration (precursor/catalyst ratio) and type (basic and acid), the precursor type (resorcinol and pyrogallol) and the solvent (aqueous or acetone based). Stoichiometric mixtures of resorcinol and formaldehyde yielded well polymerized gels and highly developed structures. Slow gelation, favored by the presence of acetone as solvent in the sol and low catalyst concentration, resulted in higher polymerization extent with a highly mesoporous or even macroporous texture and more ordered structure, as evidenced by XPS and Raman spectroscopy. Small Pt particles of ca. 3.5 nm were obtained by using carbon xerogels characterized by an ordered surface structure. The specific activity towards the oxygen reduction reaction, i.e., the limiting catalytic process in low temperature fuel cells, is significantly favored by highly ordered carbon xerogels due to a metal-support enhanced interaction. Nevertheless, surface defects favor the distribution of the metallic particles on the surface of carbon, which in the end influences the effectiveness of the catalyst. Accelerated degradation tests were conducted to evaluate catalyst stability under potential cycling conditions. The observed decay of performance was considerably lower for the catalysts based on ordered carbon xerogels stabilizing Pt particles in a higher extent than the other xerogels and the commercial carbon black support.

Energy Efficiency Enhancement of Ethanol Electrooxidation on Pd–CeO2/C in Passive and Active Polymer Electrolyte‐Membrane Fuel Cells

Pd nanoparticles have been generated by performing an electroless procedure on a mixed ceria (CeO(2))/carbon black (Vulcan XC-72) support. The resulting material, Pd-CeO(2)/C, has been characterized by means of transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and X-ray diffraction (XRD) techniques. Electrodes coated with Pd-CeO(2)/C have been scrutinized for the oxidation of ethanol in alkaline media in half cells as well as in passive and active direct ethanol fuel cells (DEFCs). Membrane electrode assemblies have been fabricated using Pd-CeO(2)/C anodes, proprietary Fe-Co cathodes, and Tokuyama anion-exchange membranes. The monoplanar passive and active DEFCs have been fed with aqueous solutions of 10 wt% ethanol and 2 M KOH, supplying power densities as high as 66 mW cm(-2) at 25 °C and 140 mW cm(-2) at 80 °C. A comparison with a standard anode electrocatalyst containing Pd nanoparticles (Pd/C) has shown that, at even metal loading and experimental conditions, the energy released by the cells with the Pd-CeO(2)/C electrocatalyst is twice as much as that supplied by the cells with the Pd/C electrocatalyst. A cyclic voltammetry study has shown that the co-support ceria contributes to the remarkable decrease of the onset oxidation potential of ethanol. It is proposed that ceria promotes the formation at low potentials of species adsorbed on Pd, Pd(I)-OH(ads), that are responsible for ethanol oxidation.

Electrochemical and Raman spectroscopic evaluation of Pt/graphitized carbon black catalyst durability for the start/stop operating condition of polymer electrolyte fuel cells

The durability of Pt nanoparticle catalysts and two types of carbon supports, carbon black (CB) and graphitized carbon black (GCB), for 50 wt% Pt-loaded catalysts (commercial Pt/CB, and Pt/GCB, heat treated (HT) Pt/GCB, and an in-house-prepared nanocapsule Pt/GCB) was evaluated by electrochemical and Raman spectroscopic methods. The Pt-loaded carbon catalysts were tested by means of a standard potential step protocol (0.9 V ↔ 1.3 V vs. RHE, holding 30 s at each potential and taking 1 min for one cycle, 3000 potential cycles for commercial Pt/CB and 10,000 cycles for commercial Pt/GCB, Pt/GCB-HT, and nanocapsule Pt/GCB) in membrane-electrode assemblies at 65 °C with 100% RH H2 (anode) and N2 (cathode). Slower degradation of the electrochemically active surface area (ECA) and smaller mass activity losses before vs. after durability testing for Pt/GCB compared to CB revealed the higher corrosion resistance of GCB. Changes in the Raman spectra were clearly detected between the Pt/GCB catalyst before and after durability testing, while only slight differences of spectra were found for commercial Pt/CB during durability testing. The degradation degree of the graphitized carbon black support was successfully evaluated from changes in the band area ratio of the G band (ca. 1575 cm−1) to the D1 band (ca. 1325 cm−1), which were estimated from curve fitting of the spectra. It was found that the type of support material, Pt nanoparticle size, as well as its dispersion state on the support, affected the degradation properties of the catalysts. The results of the Raman spectroscopic measurements demonstrated the applicability of this technique for the evaluation of the state of the graphitized carbon black-supported Pt catalysts.

Improvement in the efficiency of an OrganoMetallic Fuel Cell by tuning the molecular architecture of the anode electrocatalyst and the nature of the carbon support

The electrooxidation of ethanol to acetate is achieved with Rh(I) diolefin amine complexes of the general formula [Rh(Y)(trop2NH)(L)] (L = PPh3, P(4-n-BuPh)3; Y = triflate, acetate; Bu = butyl) in direct alcohol fuel cells that have the peculiarity of containing a molecular anode electrocatalyst and, hence, are denoted as OrganoMetallic Fuel Cells (OMFCs). Changing the carbon black support from Vulcan XC-72 (Cv) to Ketjenblack EC 600JD (Ck) and/or the axial phosphane to produce non crystalline complexes has been found to remarkably change the electrochemical properties of the organorhodium catalysts, especially in terms of specific activity and durability. An in-depth study has shown that either Ck or P(4-n-butylPh)3 favour the formation of an amorphous Rh-acetato phase on the electrode, leading to a much more efficient and recyclable catalyst as compared to a crystalline Rh-acetate complex which is formed on Cv with PPh3 as the ligand. The ameliorating effect of the amorphous phase has been ascribed to its higher number of surface complex molecules as compared to the crystalline phase. A specific activity as high as 10 000 A gRh−1 has been found in a half cell, which is the highest value ever reported for ethanol electrooxidation.

Electrochemically stabilised quinone based electrode composites for Li-ion batteries

In order to improve the stability and kinetics of organic materials for lithium batteries, composites between a quinone derivative of calyx[4]arene and carbon black were prepared. Two different approaches were used, the first relying on covalent grafting and the second on electrochemical grafting of the quinone derivatives on the carbon black support. The properties of prepared composites were investigated using XRD, FTIR, TGA and NMR, while their electrochemical stability was studied using classical galvanostatical cycling. It was found that the efficiency of the electrochemical stabilisation of organic molecules depends on the surface properties of the substrate. Interestingly, within the same compositional range, the covalently and electrochemically grafted quinone derivatives of calyx[4]arene showed similar cycling stability. Composites with approximately 20 wt.% of active organic material showed excellent cycling stability within 100 cycles with a delivered capacity of about 60 mAh g −1 of composite (more than 300 mAh g −1 per quinone).

Pd–Ni electrocatalysts for efficient ethanol oxidation reaction in alkaline electrolyte

Pd xNi y/C catalysts with high ethanol oxidation reaction (EOR) activity in alkaline solution have been prepared through a solution phase-based nanocapsule method. XRD and TEM show Pd xNi y nanoparticles with a small average diameter (2.4–3.2 nm) and narrow size distribution (1–6 nm) were homogeneously dispersed on carbon black XC-72 support. The EOR onset potential on Pd 4Ni 5/C (−801 mV vs. Hg/HgO) was observed shifted 180 mV more negative than that of Pd/C. Its exchange current density was 33 times higher than that of Pd/C (41.3 × 10 −7 A/cm 2 vs. 1.24 × 10 −7 A/cm 2). After a 10,000-s chronoamperometry test at −0.5 V ( vs Hg/HgO), the EOR mass activity of Pd 2Ni 3/C survived at 1.71 mA/mg, while that of Pd/C had dropped to 0, indicating Pd xNi y/C catalysts have a better ’detoxification’ ability for EOR than Pd/C. We propose that surface Ni could promote refreshing Pd active sites, thus enhancing the overall ethanol oxidation kinetics. The nanocapsule method is able to not only control over the diameter and size distribution of Pd–Ni particles, but also facilitate the formation of more efficient contacts between Pd and Ni on the catalyst surface, which is the key to improving the EOR activity.

Carbon-supported PtAu alloy nanoparticle catalysts for enhanced electrocatalytic oxidation of formic acid

The understanding of the electrocatalytic activity of bimetallic nanoparticle catalysts requires the ability to precisely control the composition and phase properties. In this report, we describe a new strategy in the preparation of a series of carbon supported platinum–gold bimetallic nanoparticles with various bimetallic compositions which were loaded onto a carbon black support and subjected subsequently by thermal treatment (Pt100−mAum/C). The Pt100−mAum/C catalysts are characterized by X-ray diffraction (XRD), transmission electron spectroscopy (TEM), and induced coupled plasma-atomic emission spectroscopy (ICP-AES). The XRD pattern for the bimetallic nanoparticles shows single-phase alloy character. This ability enabled us to establish the correlation between the bimetallic composition and the electrocatalytic activity for formic acid (FA) electrooxidation. The electrocatalytic activities of the catalysts toward FA oxidation reaction are shown to strongly depend on the bimetallic PtAu composition. Within a wide range of bimetallic composition, the Pt50Au50/C catalyst shows the highest electrocatalytic activity for the FA oxidation, with a mass activity eight times higher than that of Pt/C. The high performance of the PtAu/C catalyst can be ascribed to the increased selectivity toward the FA dehydrogenation at the decreased availability of adjacent Pt atoms.