Reducing the Pt-based electrocatalysts to sub-nanometer sizes is an effective way to achieve high utilization of noble metals. Herein, we report a successive route to synthesize carbon-supported bimetallic ruthenium–platinum electrocatalysts (Ru–Pt/C) with uniform dispersion and fine sizes. In this strategy, carbon-supported Ru nanoparticles (Ru/C) with a mean size of 1.4 nm are firstly prepared in a mixture of ethylene glycol and water, and the Pt precursors are then reduced in the presence of pre-formed Ru/C. The average diameter of the bimetallic Ru–Pt particles on carbon supports is 1.9 nm, which corresponds to one to two Pt layers deposited on the surface of Ru seeds. The as-prepared bimetallic Ru–Pt/C electrocatalysts are analyzed by the CO stripping voltammetry, a diagnostic electrochemical tool. Compared with the commercial PtRu/C catalyst and the control PtRu/C prepared by a conventional co-reduction method, the bimetallic Ru–Pt/C has higher electrochemical surface area (92.5 m2 g−1) and mass activity (483 A g−1) for methanol oxidation reaction. The strategy reported in this study is effective to produce fine bimetallic Ru–Pt particles (less than 2.0 nm) with uniform dispersion and high activity.

•H2 reduction of Pt(IV) in EG/water solvent was used to produce Pt nanoparticles.•EG/water = 1:1 is the optimal volume ratio to synthesize 3 nm Pt nanoparticles.•Pt(50)/CNT exhibited excellent methanol oxidation and oxygen reduction activities.Polyol approach is commonly used in synthesizing Pt nanoparticles in polymer electrolyte membrane fuel cells. However, the application of this process consumes a great deal of time and energy, as the reduction of precursors requires elevated temperatures and several hours. Moreover, the ethylene glycol and its oxidizing products bound to Pt are difficult to remove. In this work, we utilize the advantages of ethylene glycol and prepare Pt nanoparticles through a room-temperature hydrogen gas reduction in an ethylene glycol/water mixed solvent, which is followed by subsequent harvesting by carbon nanotubes as electrocatalysts. This method is simple, facile, and time-efficient, as the entire room-temperature reduction process is completed in a few minutes. As the solvent changes from water to an ethylene glycol/water mix, the size of Pt nanoparticles varies from 10 to 3 nm and their shape transitions from polyhedral to spherical. Pt nanoparticles prepared in a 1:1 volume ratio mixture of ethylene glycol/water are uniformly dispersed with an average size of ∼3 nm. The optimized carbon nanotube-supported Pt electrocatalyst exhibits excellent methanol oxidation and oxygen reduction activities. This work demonstrates the potential use of mixed solvents as an approach in materials synthesis.

•TiO2@Ru was synthesized by a modified polyol process followed by Pt deposition.•The average size of Ru and Pt was 1.5 and 2.3 nm with uniform dispersion.•TiO2@Ru wedged in between carbon particles resulted in interpenetrated network.•Pt/TiO2@Ru-C showed high utilization efficiency and stability.Aimed at high Pt utilization efficiency and stability, Pt/TiO2@Ru-C electrocatalysts have been prepared by a two-stage modified polyol process, in which ruthenium nanoparticles are dotted on TiO2 nano-bricks to form TiO2@Ru in the first stage, followed by deposition of platinum nanoparticles on either the in-situ formed TiO2@Ru or carbon black in the second stage. The electrocatalysts have been characterized by Transmission Electron Microscopy, X-ray Diffraction and Thermogravimetric analysis. The electrochemical surface area of the Pt/TiO2@Ru-C is 82.9 m2 g−1 and remains to as high as 44.8 m2 g−1 in an accelerated stability test. Catalytic activity towards methanol oxidation reaction of the catalyst in 0.5 M CH3OH + 0.5 M H2SO4 at room temperature is found to be 487 A g−1. TiO2 nano-bricks are wedged in between the interfaces of carbon particles creating interpenetrated TiO2-Pt-C network, making them easily accessible to fuel cell reactions. Meanwhile, the interpenetrated TiO2 prevent the electrocatalyst from agglomeration, leading to high Pt efficiency as well as durability.

•H2 reduction of Pd(II) in EG was used to produce uniform Pd nanoparticles.•Pd/C showed high stability in 1000 potential cycles.•TEM for Pd/C after potential cycles disclosed the origin of Pd deactivation.In this work, a Pd/C catalyst with high activity as well as excellent stability has been prepared by hydrogen gas reduction of Pd(II) precursor in ethylene glycol solution with the assistance of appropriate amount of sodium citrate. Pd nanoparticles with an average particle size of 3.8 nm and excellent uniformity are obtained. The Pd/C catalyst synthesized in this work shows an electrochemical surface area of 68.6 m2 g−1 and displays activities of 819 A g−1. Strikingly, the Pd/C catalyst also exhibits excellent stability, which has been confirmed by its slow activity decay under repeated potential cycles as well as chronoamperometric test. The activity for Pd/C at the 300th and 500th cycle remains at 5.5 and 2.4 mA cm−2, respectively, which is 25% and 11% of its initial value, respectively. The oxidation currents at the Pd/C and Pd/C-Citrate (control) at 0 V decrease to 44% and 25% of their initial values. Transmission electron microscopy observations on the Pd/C catalyst after 1000 potential cycles reveal that, in addition to carbon support corrosion, Pd agglomeration together with more serious Pd dissolution occur at the same time, leading to a decrease of the electrocatalytic performance.

•TiO2-Co3O4-C composite support (CS) was synthesized and used to load 40.3 wt.% Pt for PEMFCs.•The composite support was more corrosion resistant than XC-72.•The Pt/CS showed slower ECSA decrease.•After 2000 potential cycles, Pt/CS showed high stability towards agglomeration.Motivated by addressing the support corrosion or stability issue for electro-catalysts, a carbon composite support has been prepared by wet-impregnation of nano-sized TiO2 and cobalt (II) acetate tetrahydrate together with XC-72 carbon black, followed by thermal treatment at 900 °C in a reductive atmosphere. Decomposition of cobalt acetate under thermal treatment yields TiO2-Co3O4-C composite support (CS), as is confirmed by X-ray diffraction analysis. The composite support is found to be more corrosion resistant and stable in acidic solution than that of the conventionally used carbon black, as is witnessed by the chronoamperometric response. This composite support is then used to load 40.3 wt.% Pt nanoparticles (Pt/CS) as an electro-catalyst for proton exchange membrane fuel cells. It is found that 27.9% of the electrochemical surface area (ECSA) retained in an accelerated stability test (AST) in 0.5 M H2SO4 for Pt/CS, compared with 8.4% for 39.5 wt.% Pt catalyst supported on XC-72 carbon black. The TEM image after AST for Pt/CS also confirms its improved resistance to agglomeration. The Pt/CS catalyst shows higher mass-normalized activity for methanol oxidation in 0.5 M CH3OH + 0.5 M H2SO4 and a slower activity decay relative to that of the benchmarked Pt catalyst on carbon.

•Electrolessly-plated copper foams were synthesized for preparation of N, P and B doped CNFs.•Doped CNFs were hydrophilic and employed as supports to anchor Pt without any functionization.•Pt/CNF was highly active and stable for ORR and was resistant to corrosion.Aimed at improved durability and catalytic activity for oxygen reduction reaction, carbon nanofibers(CNFs) with nitrogen, phosphorus and boron dopants have been synthesized by chemical vapor deposition of acetylene on electrolessly-plated copper foams. The as-prepared CNFs were extensively characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy and Raman analysis. Without any functionalization, the as-prepared CNF was employed as support for 40 wt.% Pt electrocatalyst (Pt/CNF). In an accelerated stability test (AST), Pt/CNF displayed higher stability relative to the state-of-the-art electrocatalyst from Johnson Matthey (Pt/C-JM) with the same Pt loading. TEM images after AST for Pt/CNF were obtained and found that the doped carbon nanofiber support is more resistant to corrosion. At the meantime, the catalytic activity to oxygen reduction for Pt/CNF surpassed Pt/C-JM by more positive on-set potential. CNFs with N, P and B dopants synthesized in this work should have promised applications for polymer electrolyte membrane fuel cells.

•PdxPty/C with an average particle size of 3 nm were prepared by a citrate reduction method with KNO3.•CO striping and repeated CV were used to test the CO tolerance and stability respectively.•The catalysts' mass activity for formic acid oxidation outperformed those from literature.Carbon supported PdxPty/C (atomic ratio x:y from 1:1 to 6:1) have been prepared by a modified citrate reduction method assisted by inorganic stabilizers. Without using high molecular capping agents as stabilizers, the PdxPty/C catalysts are highly dispersed on the carbon support and no particle aggregations are found for the PdxPty/C catalysts. X-ray photoelectron spectroscopy reveals either Pt or Pd segregation for the PdxPty/C catalysts depending on Pd/Pt atomic ratio. CO stripping in 0.5 M H2SO4 and repeated formic acid oxidation cyclic voltammetry in 0.5 M HCHO + 0.5 M H2SO4 have been conducted to test out the CO tolerance and stability of the catalysts, respectively. It has been found that, with the increase of Pd/Pt atomic ratio, the CO stripping peak potential increases (less CO tolerant), whereas the catalyst stability towards formic acid oxidation decreases. The as-prepared catalysts reveal excellent mass-normalized formic acid oxidation activity as compared with published results possibly due to high dispersion and the absence of high molecular capping agents.

•A polyol reduction approach was employed to prepare highly active PtOs/C for methanol oxidation.•The catalysts' physical characteristics correlated with their electrochemical performances.•Activity improvement was attributed to a mix of nanoparticles, high metallic Os and small sizes.•The mass and specific activity of PtOs-2/C is 528 mA mg−1PtOs and 0.98 mA cm−2, respectively.A polyol reduction approach was employed to prepare carbon-supported PtOs/C electrocatalysts (PtOs-1/C was obtained via the co-reduction of H2PtCl6 and K2OsCl6 precursors and PtOs-2/C was obtained via a sequential deposition method in which Pt was deposited on the preformed Os nanoparticles). The home-made electrocatalysts were extensively characterized via transmission electron microscopy, thermogravimetric analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. The evaluation results of the catalytic activities obtained via cyclic voltammetry, CO stripping voltammetry, and chronoamperometry showed that the successively reduced PtOs-2/C out-performed PtOs-1/C in terms of specific/mass activity (528 mA mg−1PtOs and 0.98 mA cm−2) and CO tolerance in room temperature methanol electrooxidation reaction. The physical characteristics of the electrocatalysts correlated well with their electrochemical performances. The higher activity of PtOs-2/C was attributed to a combination of factors, such as a mix of nanoparticles (isolated Os, PtOs alloys or bimetallic nanoparticles), higher metallic Os content, and smaller particle sizes.

•CeO2–C composite support was prepared by a sol-gel approach with an average particle size of 2.5 nm.•The crystallinity of ceria was tuned by thermal treatment from 400 °C to 600 °C.•Well correlated Pt–ceria interaction was found for the Pt electrocatalysts in PEMFCs.A sol–gel approach was used to synthesize highly dispersed carbon-supported ceria composite support (CeO2–C) having an average particle size of 2.5 nm with sodium citrate as a ligand. The CeO2–C composite was then heated in N2 atmosphere at different temperatures to induce crystallinity variation. Pt electrocatalysts were prepared by the conventional ethylene glycol method using the thermally treated composite support (CeO2–C-T) and then characterized by X-ray diffraction and transmission electron microscopy. Electrochemical evaluations of Pt/CeO2–C-T catalytic activity were performed for methanol oxidation and oxygen reduction reactions. An optimized heating temperature was found at 550 °C for CeO2–C, and Pt/CeO2–C-550 demonstrated the highest mass activity of 0.71 A mg−1 for methanol oxidation (∼100% that of Pt/C-JM from Johnson Matthey) and 17 mV more positive shift of the half-wave potential for oxygen reduction relative to that of Pt/C–JM. The maximum power density of the membrane electrode assembly (MEA) with Pt/CeO2–C-550 cathode catalyst in a H2/air polymer electrolyte membrane fuel cell was 678 mW cm−2, which was 7% higher than that of MEA prepared with Pt/C–JM under identical operating conditions. Heating CeO2–C at 550 °C induced increased crystallinity without sacrificing particle agglomeration, which was beneficial for Pt dispersion (reduced particle size). Meanwhile catalytic activity was further enhanced because of Pt–metal oxide interactions and the known oxygen buffer capability of CeO2.

•A modified citrate reduction method assisted by inorganic salt stabilization was developed.•Open circuit potentials were measured and used to account for Pt hydrosol stability;.•The home-made Pt/C outperformed a commercial one with a 65% mass activity enhancement.Without presence of high molecular weight capping agents, tiny Pt nanoparticles (<3 nm) are prone to agglomeration due to Oswald ripening. However, the use of capping agents will block the active sites of Pt nanoparticles, making them catalytically inefficient in polymer electrolyte membrane fuel cells. In this work, we have developed a modified citrate reduction method assisted by inorganic salt stabilization for the preparation of very stable and highly dispersed Pt hydrosols (2.0 nm). The addition of inorganic salt (stabilizing Pt hydrosols through a thicker electrostatic double layer) significantly reduces the citrate amount (Cyt3−/Pt4+ = 1:1), therefore the conventionally used post heat treatment to remove excess citrate is unnecessary for carbon supported Pt electrocatalysts. The open circuit potentials of the Pt precursors are measured, and most probably the first time used to account for the Pt hydrosol stability and correlated with zeta potential measurement and TEM imaging. The carbon supported Pt electrocatalysts prepared in this work exhibit high mass activity toward methanol oxidation (as a probe reaction) relative to commercially available Pt/C electrocatalysts.

Commercially available carbon-supported Pt, PtCo and PtRu catalysts from E-TEK are heat-treated in turn at 600 °C and 800 °C each for an hour. The as-received and as-heated catalysts are used as anode catalysts for direct methanol fuel cells. Structural and surface composition changes induced by heating are analyzed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. For the Pt catalyst, heating the catalysts caused only the mass activity decrease due to particle sintering, whereas the specific activity and CO tolerance remained unchanged. The performance of the PtCo and PtRu catalysts is affected differently by heating. Heating the PtRu catalyst adversely affects its catalytic activity and its CO tolerance due to Pt depletion at the surface. In contrast, although Pt depletion also takes place for the heated PtCo catalysts, these catalysts show an even higher specific activity and approximately the same CO tolerance. The observed difference is likely due to the optimum atomic ratio difference for Ru/Pt and Co/Pt; an increased atomic ratio on the surface for Co/Pt results in an activity enhancement, which is contrary to the effect of the increase of Ru/Pt atomic ratio.Graphical abstractXRD patterns of the PtCo/C, PtCo/C-600 and PtCo/C-800 catalysts.Highlights► Carbon supported Pt, PtCo, PtRu catalysts are subjected to heat-treatment. ► Heating induced structural changes of the catalysts were investigated. ► Different performance of heated PtCo, PtRu catalysts is likely due to difference in atomic ratios.

•Positively charged Ru (1.0 nm, +6.6 mV) and negatively charged Pt nanoparticles (2.2 nm, −4.2 mV) are synthesized by a surfactant-free manner.•Highly ordered PtxRuy nanocomposites are electrostatically self-assembled upon mixing.•CO oxidation and MOR activities of the PtxRuy/C are highly dependent on Pt/Ru ratio and all demonstrate enhanced activity.Positively charged Ru nanoparticles (∼1.0 nm, zeta potential = +6.6 mV) induced by hydrated protons and negatively charged Pt nanoparticles (∼2.2 nm, zeta potential = −4.2 mV) by NO3− are synthesized separately. Without use of any high molecular weight surfactants, oppositely charged surfactant-free Ru and Pt colloids display sustained stability. Highly ordered PtxRuy nanocomposites are electrostatically self assembled when the oppositely charged Ru and Pt colloids were mixed at room temperature. CO stripping voltammograms of PtxRuy/C show that the CO stripping peak and the on-set oxidation potential are highly dependent on Pt/Ru ratio, which is most probably due to the different interstitial space between Pt and Ru in the self-assembled patterns. The mass-normalized activity of Pt3Ru1/C for methanol oxidation reaction is found to be 112% higher relative to that of PtRu/C catalyst from E-TEK.

The conventional hydrogen gas reduction method for preparation of platinum nanoparticles is to bubble H2 gas into solution with a pre-existing platinum precursor. In this work, instead of bubbling hydrogen gas into Pt precursor solution, we reverse the addition sequence by quickly injecting the Pt precursor into a solution saturated with hydrogen gas. Colloidal Pt nanoparticles thus synthesized are polyhedra of different shapes. Carbon-supported Pt catalysts (Pt-1/C) are prepared by subsequently harvesting the Pt colloids and testing for the methanol oxidation reaction at room temperature. Transmission electron microscope (TEM) images are used to observe the Pt nanoparticle morphology and UV-vis spectra are used to monitor Pt precursor reduction with time. The Pt loadings are confirmed by thermogravimetric analysis. Interestingly, CO stripping cyclic voltammetry of Pt-1/C displayed double oxidation peaks with comparable intensities, one of which is 120 mV more negative than that of a typical CO oxidation peak on Pt. Besides the improved CO tolerance, Pt-1/C easily surpasses the mass activity of Pt/C from E-TEK by 55%. The method reported in this work presents a simple and eco-friendly route for producing carbon-supported platinum electrocatalysts with enhanced CO tolerance and mass activity.

Highly dispersed Ru/C catalysts are prepared using high viscosity glycerol as a reducing agent and are treated in H2 atmosphere to ensure stability. A Pt∧Ru/C catalyst is prepared by an ethylene glycol process based on the pre-formed Ru/C. The catalyst is tested for methanol oxidation reaction at room temperature and is compared with the activity of the as-prepared PtRu/C alloyed catalyst (prepared by co-reduction of Pt and Ru precursors) and commercial PtRu/C from E-TEK. The catalysts are extensively characterized by Transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Electrochemical measurements by cyclic voltammetry (CV) showed consistently high catalytic activities and improved CO resistance for the Pt∧Ru/C catalyst.Highlights► High viscosity glycerol as effective reducing agent is used to produce highly dispersed Ru/C. ► Pt∧Ru/C is composed of isolated Pt and Pt-on-Ru core–shell nanoparticles, which is attributed to the enhanced activity. ► Pt∧Ru/C registered higher catalytic activity relative to commercial E-TEK PtRu/C.

Platinum decorated Ru/C catalysts are prepared by successive reduction of a platinum precursor on pre-formed Ru/C. Pt:Ru atomic ratios are varied from 0.13:1 to 0.81:1 to investigate the platinum decoration effects on the catalyst's structure and electrochemical performance towards the methanol oxidation reaction (MOR) at room temperature. The catalysts are extensively characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Ru@Pt/C catalysts show enhanced mass-normalized activity and specific activity for the MOR relative to Pt/C. For the anodic oxidation of methanol, the ratio of forward to reverse oxidation peak current R (If/Ib) varies considerably: R decreases from 5.8 to 0.8 when the Pt:Ru ratio increases from 0.13:1 to 0.81:1. When the ratio of Pt:Ru is 0.42:1, R reaches 0.99 (close to that of Pt/C), and further increase of the Pt:Ru ratio leads to almost no decrease in R. Coincidentally, maximum mass-normalized activity is also obtained when Pt:Ru is 0.42:1.

Carbon-supported core–shell structured Ru@PtxPdy/C catalysts with PtxPdy as shell and nano-sized Ru as core are prepared by a successive reduction procedure. The catalysts are extensively characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The formic acid oxidation activity of Ru@PtxPdy/C varies with the varying Pt:Pd atomic ratio. The peak oxidation potential on Ru@Pt1Pd2/C shifts negatively for about 200 mV compared with that of Pd/C. The higher electro-catalytic activity toward formic acid oxidation on core–shell structured Ru@PtxPdy/C catalyst than that on PtxPdy/C suggests the high utilization of noble metals. In addition to the enhanced noble metal utilization, Ru@PtxPdy/C catalyst also shows improved stability as evidenced by chronoamperometric evaluations.

Pt/C, Pd/C and PdPt/C catalysts are potential anodic candidates for electro-oxidation of formic acid. In this work we designed a miniature air breathing direct formic acid fuel cell, in which gold plated printed circuit boards are used as end plates and current collectors, and evaluated the effects of anode catalysts on open circuit voltage, power density and long-term discharging stability of the cell. It was found that the cell performance was strongly anode catalyst dependent. Pd/C demonstrated good catalytic activity but poor stability. A maximum power density of 25.1 mW cm−2 was achieved when 5.0 M HCOOH was fed as electrolyte. Pt/C and PdPt/C showed poor activity but good stability, and the cell can discharge for about 10 h at 0.45 V (Pt/C anode) and 15 h at 0.3 V (PdPt/C) at 20 mA.Highlights► A miniature air breathing DFAFC with focus on the effects of anode catalysts was designed and evaluated. ► The cell performance, stability, Faradic/energy efficiency was strongly anode catalyst dependent. ► Pd/C have good catalytic activity but with poor stability. ► Pt/C and PdPt/C as anode catalyst have poor activity but with good stability.

A miniature air breathing compact direct formic acid fuel cell (DFAFC), with gold covered printed circuit board (PCB) as current collectors and back boards, is designed, fabricated and evaluated. Effects of formic acid concentration and catalyst loading (anodic palladium loading and cathodic platinum loading) on the cell performance are investigated and optimized fuel concentration and catalyst loading are obtained based on experimental results. A maximum power density of 19.6 mW cm−2 is achieved at room temperature with passive operational mode when 5.0 M formic acid is fed and 1 mg cm−2 catalyst at both electrodes is used. The home-made DFAFC also displays good long-term stability at constant current density.

Electrocatalytic activity for oxygen reduction reaction on magnetically modified PtFe/C catalysts was investigated. X-ray powder diffraction (XRD) revealed that while the as-prepared PtFe/C catalysts were face-centered cubic (f.c.c), the as annealed catalysts at 700° for 3 h were face-centered tetragonal (f.c.t). Post-heating transformed the as-prepared catalysts from superparamagnetic into ferromagnetic materials as was measured by vibrating sample magnetometer (VSM). Electrochemical results obtained by rotating disk electrode (RDE) technique showed that oxygen reduction reaction took place by an overall four electron charge transfer process. Polarization curves showed that the electrocatalytic activity on ferromagnetic catalyst for oxygen reduction obviously outperformed the as-prepared paramagnetic catalyst. The values of kinetic parameters for the as-prepared and as-heated catalysts were obtained from linear-line region of mass-transfer-corrected Tafel plots. The catalytic enhancement by the magnetically modified catalyst was explained by the magnetic attractive force toward oxygen thus increasing electrochemical flux at the heterogeneous catalytic interface.

ac etching of high-purity aluminum foils in hybrid acids including hydrochloric acid, sulphuric acid and oxalic acid was investigated and the effects of ultrasonic-assisted stirring on the performances of the etched foils were investigated in this work. Scanning electron microscopy (SEM) was used for observation of the etched foils. Compared with the classically used mechanical stirring (magnetic stirring), the assistance of ultrasonic increased the performance of the etched foil. With 20 V forming voltage, the static capacitance and bending strength of the foils etched with ultrasonic stirring reached 76.5 μF cm−2 and 98 times compared with 71.2 μF cm−2 and 85 times respectively for the foils fabricated with magnetic stirring using 100 μm aluminum foils. The performance enhancement with the assistance of ultrasonic is probably due to the cavitation effects which are beneficial for the remove of protective layer and the dispersion effects which reduce concentration polarization in the bulk etchant solutions.

The conventional hydrogen gas reduction method for preparation of platinum nanoparticles is to bubble H2 gas into solution with a pre-existing platinum precursor. In this work, instead of bubbling hydrogen gas into Pt precursor solution, we reverse the addition sequence by quickly injecting the Pt precursor into a solution saturated with hydrogen gas. Colloidal Pt nanoparticles thus synthesized are polyhedra of different shapes. Carbon-supported Pt catalysts (Pt-1/C) are prepared by subsequently harvesting the Pt colloids and testing for the methanol oxidation reaction at room temperature. Transmission electron microscope (TEM) images are used to observe the Pt nanoparticle morphology and UV-vis spectra are used to monitor Pt precursor reduction with time. The Pt loadings are confirmed by thermogravimetric analysis. Interestingly, CO stripping cyclic voltammetry of Pt-1/C displayed double oxidation peaks with comparable intensities, one of which is 120 mV more negative than that of a typical CO oxidation peak on Pt. Besides the improved CO tolerance, Pt-1/C easily surpasses the mass activity of Pt/C from E-TEK by 55%. The method reported in this work presents a simple and eco-friendly route for producing carbon-supported platinum electrocatalysts with enhanced CO tolerance and mass activity.