PtPd Alloy Research Articles

One-pot synthesis of efficient reduced graphene oxide supported binary Pt-Pd alloy nanoparticles as superior electro-catalyst and its electro-catalytic performance toward methanol electro-oxidation reaction in direct methanol fuel cell

The development of the clean synthesis of efficient bimetallic Pt-Pd alloy nanoparticles supported reduced graphene oxide (RGO) catalyst (RGO/Pt-Pd) through a facile, rapid, surfactant–free and novel one-pot process of chemical reduction-assisted hydrothermal reaction using formic acid as reducing agent have been introduced. The structural, elemental composition analysis and surface morphology of the as-prepared catalysts were extensively characterized by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, energy dispersive x-ray spectroscopy (EDX), high resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM), respectively. The electrochemical properties, catalytic activity and long-term stability performance of the RGO/Pt-Pd nanocomposite catalyst were employed by cyclic voltammogram and chronoamperometry. Furthermore, owing to the synergetic effects of Pt and Pd nanoparticles, the unique structure of Pt-Pd alloy nanoparticles and enhanced electron transfer by RGO, the as-synthesized RGO/Pt-Pd nanocomposite catalyst has demonstrated the enlarged electrochemical surface area (ECSA) (ECSA = 0.91 cm2), remarkably higher electro-catalytic activity (If = 59.6 mA/cm2) and enhanced stability as compared to RGO/Pt (If = 23.32 mA/cm2, ECSA = 0.18 cm2) and RGO/Pd (If = 8.65 mA/cm2, ECSA = 0.11 cm2) nanocomposite catalysts toward methanol oxidation reaction (MOR). This superior catalytic activity of the as-prepared RGO/Pt-Pd nanocomposite catalyst with facile and simple preparation approach is promising a great opportunity for the development of direct methanol fuel cell.

CO2 plasticization effect and selectivity for Pt-Pd alloy coated polycarbonate membrane

The transport of CO2 through variety of polymer membrane has been reported since last few years. CO2 shows plasticizing effect with glassy polymers facilitating molecular motion and increasing free volume which promotes the permeability. In this work, the transport behaviour of CO2 across the metal coated membrane has been studied and compared with that of standard polycarbonate membrane as a function of pressure. Deposition of nanolayer affects the transport properties due to the modification in sorption-diffusion process. As CO2 is a plasticizing agent and at definite pressure it gives plasticizing effect depending on the properties of material. A Platinum-Palladium (Pt-Pd) alloy thin film of around 8–10 nm was coated on thick polycarbonate (PC) substrate using sputtering technique to make layered polymer nanocomposite membrane. The permeability decreases with feed pressure for PC/Pt-Pd. As operating pressure is increased, the diffusion coefficient increases with small change and the solubility decreases. The tests were carried out at different upstream pressures i.e. in the range of 30 psi to 230 psi (2 atm to 16 atm) for PC/Pt-Pd at 35 °C temperature. Further, the selectivity of CO2 over H2, O2 and N2 at various upstream pressures has been reported.

Fabrication of bilayer Pd-Pt nanocages with sub-nanometer thin shells for enhanced hydrogen evolution reaction

The hydrogen evolution reaction (HER), which generates molecular hydrogen through the electrochemical reduction of water, is an important clean-energy technology. Platinum (Pt) is an ideal material for HER electrocatalysts in terms of low overpotential and fast kinetics. An effective method to improve the atom utilization efficiency of Pt is to fabricate Pt-based core-shell or nanocage structures with ultra-thin walls. This paper describes the construction of bilayer palladium (Pd)-Pt alloy nanocages catalyst with enhanced HER catalytic activity. The nanocages were fabricated by etching away the Pd templates of multishelled nanocubes composed of alternate shells of Pd and Pt with well-defined (100) facets. The bilayer Pd-Pt nanocages with sub-nanometer shells have a high dispersion of the active atoms on the outside and inside surfaces of outer layer and inner layer, respectively. Moreover, the Pd-Pt alloy lowers the overpotential for HER and speeds up the reaction rate of HER due to the synergies between Pd and Pt. The rational design of bilayer nanocages provided a novel route for boosting the atom utilization efficiency of Pt catalysts.

Novel PtPd alloy nanoparticle-decorated g-C3N4 nanosheets with enhanced photocatalytic activity for H2 evolution under visible light irradiation

PtPd bimetallic alloy nanoparticle (NP)-modified graphitic carbon nitride (g-C3N4) nanosheet photocatalysts were synthesized via chemical deposition precipitation. Characterization of the photocatalytic H2 evolution of the g-C3N4 nanosheets shows that it was significantly enhanced when PtPd alloy NPs were introduced as a co-catalyst. The 0.2 wt% PtPd/g-C3N4 composite photocatalyst gave a maximum H2 production rate of 1600.8 μmol g–1 h–1. Furthermore, when K2HPO4 was added to the reaction system, the H2 production rate increased to 2885.0 μmol g–1 h–1. The PtPd/g-C3N4 photocatalyst showed satisfactory photocatalytic stability and was able to maintain most of its photocatalytic activity after four experimental photocatalytic cycles. In addition, a possible mechanism for the enhanced photocatalytic activity was proposed and verified by various photoelectric techniques. These results demonstrate that the synergistic effect between PtPd and g-C3N4 helps to greatly improve the photocatalytic activity of the composite photocatalyst.

Porous PtPd alloy nanotubes: towards high performance electrocatalysts with low Pt-loading

Porous PtPd alloy nanotubes with Pt contents down to 5 at% are powerful, Pt-lean electrocatalysts.

One-pot synthesis of unprotected PtPd nanoclusters with enhanced catalytic activity, durability, and methanol-tolerance for oxygen reduction reaction

Bimetallic PtPd alloys are regarded as promising high performance oxygen reduction reaction (ORR) catalysts. However, the application of a subnanometer scale PtPd bimetallic nanoclusters (NCs) is rarely studied. In this work, ordered mesoporous carbon (OMC) supported PtPd NCs with the constant metal loading of 10 wt% and various Pt:Pd atomic ratios were synthesized by a modified polyol reduction route. The PtPd NCs show a maximum activity at Pt:Pd molar ratio close to 3:1 with a mean size of ∼2.35 nm. The specific activity (SA) and mass activity (MA) of Pt3Pd1 NCs/OMC (PtPd loading: 10 wt%) is 2.5 and 4.1 times higher than those of the commercial Pt/C (Pt loading: 20 wt%) in 0.1 M HClO4. Meanwhile, the Pt3Pd1 NCs/OMC exhibits improved methanol tolerance and durability for ORR. Therefore, the Pt3Pd1 NCs/OMC is excellent candidate that may become a practical cathode catalyst for fuel cells.

Facile synthesis of PtPd/SnO2 nanocatalysts with good photo-electrocatalytic property

PtPd/SnO2 nanocatalysts were synthesized by a simple one-step way of plasma technique in an aqueous solution of tin(II) chloride by using Pt and Pd metal wire as the electrode pair. PtPd/SnO2/GNs composite catalysts were prepared by an ultrasonic mixing PtPd/SnO2 with GNs (GNs, graphene nanosheets). The PtPd/SnO2/GNs composite catalysts exhibit a significantly enhanced electrocatalytic performance, cycling stability and CO-poisoning tolerance towards methanol oxidation both under acidic and alkaline condition, which attributed to the synergism of PtPd alloy and SnO2. What’s more, the current density of PtPd/SnO2/GNs composite catalyst was obviously improved under light illumination, with 10,029 mA mgPt−1 which was about 1.3 times higher than that without light illumination under alkaline condition. The novel one-step plasma technique could provide a useful approach for fabricating other highly efficient electrocatalysts.

Engineering and understanding of synergistic effects in the interfaces of rGO-CNTs/PtPd nanocomposite revealed fast electro-oxidation of methanol

The developing human societies are being faced provoking energy crises due to higher demands of energy for increasing worldwide populations. The massive depletion of natural resources and global warming issues sound a laud alarm for modern societies. Methanol is attracting huge attractions as an alternative fuel in direct methanol fuel cells for the development of future energy conversion resources, while the fast chemisorptions of methanol and stable performance remained a challenge thereby hampering their scalable applications at commercial level. Herein, we focused on these goals by alteration in chemistry of materials being used as anode catalysts for direct methanol fuel cells. The promising PtPd alloy nanoparticles with tailored compositions are loaded on highly conductive rGO-CNTs support material. The highly active components of the metals and powerful electron transfer material as a support, these combined characteristics in one nanostructure facilitate the fast chemisorptions of methanol with durable performance. The ex-situ electrochemical and in-situ online differential electrochemical mass spectrometric analysis reveal the enhanced electrocatalytic methanol oxidation reaction activities attribute towards direct chemisorptions intermediate pathways introduced via geometric and structural factor within nanocomposite material.

One-step electrodeposition of ligand-free PdPt alloy nanoparticles from water droplets: Controlling size, coverage, and elemental stoichiometry

We present a robust and facile method to produce metal nanoparticle (NP) alloys in a one-step synthesis using direct electrodeposition onto highly oriented pyrolytic graphite (HOPG). Precursor salts, H2PtCl6 and Pd(NO3)2, were dissolved in a 1 mM sodium dodecylsulfate (SDS) water droplet with 1× phosphate buffered saline solution and suspended in a dichloroethane (DCE) continuous phase. Tetrabutylammonium perchlorate was added to the DCE continuous phase to maintain charge balance during electrodeposition. NP fabrication via electrodeposition was driven by droplet collisions onto HOPG, which was biased at a potential where the metal precursor salts would reduce to their respective zero-valent atoms. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) were used to study the size, coverage, and morphology of the NPs as well as the atomic stoichiometry. EDX mapping indicated homogeneous distribution of Pd and Pt at the single NP level. Homogeneously alloyed PdPt NPs were realized from this study with demonstrated control over metal composition, surface coverage, and NP size.

A dopamine electrochemical sensor based on Pd-Pt alloy nanoparticles decorated polyoxometalate and multiwalled carbon nanotubes

A novel sensor was assembled for electrochemical sensing of dopamine (DA) based Pd-Pt alloy nanoparticles (Pd@Pt) decorated polyoxometalate (PMo9V3) on the surface of indium‑tin oxide (ITO) electrodes which was pre-modified by multiwalled carbon nanotubes (CNTs). The surface morphology of the sensor was recorded by scanning electron microscope (SEM), and the elements on the modified electrode were characterized from a representation of X-ray photoelectron spectroscopy (XPS). The combination of Pd@Pt and CNTs with PMo9V3 significantly enhanced the peak response current and decreased the overpotential of dopamine oxidation. Meanwhile the oxidation reaction of dopamine can be separated from ascorbic acid and uric acid, improving the selectivity of the sensor. The as-fabricated sensor exhibited a wide linear response of 2.50 × 10−8 to 1.78 × 10−4 M, low detection limit of 1.25 × 10−8 M (S/N = 3) and short response time (<1.0 s). Furthermore, the sensor was employed for determination of DA in human serum and dopamine hydrochloride injection, which manifested the potential application of the modified electrode.

Facile morphology controllable synthesis of PtPd nanorods on graphene-multiwalled carbon nanotube hybrid support as efficient electrocatalysts for oxygen reduction reaction

One-dimensional (1D) anisotropic platinum-based nanorods are particularly attractive electrocatalysts for oxygen reduction reaction (ORR) owing to the inherent structural advantages. In this work, we report the growth of ultrathin PtPd alloy nanorods (3–4 nm) on Graphene-Multiwalled carbon nanotube (G–M) hybrid support via a facile surfactant-free and template-free method as the efficient electrocatalyst for ORR. The as-synthesized PtPd NRs/G–M catalyst exhibits more excellent activity and better durability toward ORR than Pt NRs/G and Pt NRs/G–M catalysts. Noteworthily, it shows an outstanding half-wave potential of 0.810 V and mass activity of 49.5 mA mg–1 at 0.85 V, which are 30 mV and 2.1 times higher than those of commercial 40 wt% Pt/C (JM40) catalyst, respectively. After the accelerated durability tests (ADTs), it also maintains superior stability than JM40. The superior performance is attributed to the combination of the advantageous 1D morphological motif and the synergistic effect with G–M support.

Engineering of Hollow PdPt Nanocrystals via Reduction Kinetic Control for Their Superior Electrocatalytic Performances.

Synthesis of hollow metal nanocrystals (NCs) is greatly attractive for their high active surface areas, which gives rise to excellent catalytic activity. Taking PdPt alloy nanostructure as an example, we designed a synthetic tactic for the preparation of hollow metal nanostructures by delicate control over the difference in the reduction kinetic of metal precursors. At a high reduction rate difference, the Pd layer forms from H2PdCl4 and is subsequently etched, leading to the formation of a hollow space. A solid PdPt structure is achieved when the reduction rate of Pd and Pt precursor is comparable. Obviously, the hollow space and composition are tunable as well by adjusting the reduction rate difference. More importantly, the prepared hollow PdPt nanostructures exhibit a branched outer, porous wall, and rough hollow interior. The branched outer and rough hollow interior provide the higher density of unsaturated atoms, whereas the porous wall serves as channels connecting the inner, outer, and reactive agents. Moreover, the periodic self-consistent density function theory suggests that the d-band theory density of state of the PdPt nanoalloys is upshifted in comparison to the monometallic component, which will beneficial for improvement in their catalytic performances. Electrocatalytic tests reveal that the PdPt bimetallic NCs, especially for Pt32Pd68 nanostructures, show excellent catalytic activity and stability toward methanol oxidation reaction owing to their special structures as well as compositions.

(Invited) Growth and Catalytic Performance of Pd and Pd-Pt Alloy Ultrathin Films on Au By Surface Limited Redox Replacement of H UPD Layers in One-Cell Configuration

In the ongoing effort of solving the energy problem of humanity the design, fabrication and testing of catalysts has been playing a central role for the last couple of decades. Besides the known application of Pd hydrogen gas storage a growing interest has been seen in the use of this metal and its alloys in catalytic reactions with relevance to fuel cells. While Pt is still considered best catalyst for fuel cell applications its high cost and limited supply calls more and more for intensifying the effort of replacing Pt with Pd. Means of growing Pd on conductive materials include a variety of expensive vacuum deposition approaches that need sophisticated equipment and high temperature. An alternative to those is electrodeposition that besides the standard bulk deposition, offers a variety of ultra-thin film growth approaches that could facilitate the deposition of uniform and flat continuous Pd films on polycrystalline Au. Among those, the electrochemical atomic layer deposition of Pd under optimum conditions was first developed for automated flow cell. Our group has been working recently on developing fine-tuned approaches for the growth of epitaxial Pd on Au using always readily available one-cell configuration instead, of sophisticated automated flow cells. The growth uses surface limited redox replacement (SLRR) reaction of underpotentially deposited (UPD) Cu or H sacrificial layers. After a set of iteratively applied deposition cycles, the as-deposited Pd or Pt-Pd films are tested for surface roughness using characteristic HUPD and CuUPD cyclic voltammetry (CV) curves and the efficiency of the deposition technique is measured by stripping charge determination. Also, XPS characterization was used for determining both, the alloy composition in the case of Pt-Pd deposition and the presence / absence of impurities incorporating in the deposit in the case of pure Pd growth. The quasi-2D growth resulting in smooth and uniform Pd-film morphology has also been confirmed up to 20 SLRR cycles by in-situ STM. Consequently, the accordingly deposited films at minimum thickness are tested for catalytic activity and durability in formic acid oxidation reactions. In this presentation results of this work will be presented in detail and critically discussed. The emphasis is on the illustration of deposition approach that has been developed to take place in one cell and in the specifically in the case of SLRR of HUPD results in a theoretically contamination free deposits. It is also demonstrated that this approach provides for maximum deposition efficiency engaging also adsorbed H in the replacement scenario. The CV results indicate the deposition of smooth Pd films taking place for up to 30 SLRR cycles for HUPD and CuUPD sacrificial layers, respectively. This is followed by a rapid transition to dendritic growth at higher thickness. The underlying kinetic reasons for such abrupt transition are also considered and critically discussed. Finally, the applicability of the proposed facile SLRR approach has been demonstrated through testing for catalytic activity and durability in formic acid oxidation of ultrathin films of Pd, Pt and Pt-Pd alloys with different composition. The critical analysis of the testing outcome suggested that a 1:2 Pt-Pd alloy exhibits activity and durability that are comparable with those of pure Pt and substantially better to those of pure Pd.

Bimetallic Pt-Pd co-catalyst Nb-doped TiO2 materials for H2 photo-production under UV and Visible light illumination

In this work we synthesized a series of binary PtPd co-catalysts supported on a Nb-doped TiO2 support. The catalytic solids and corresponding monometallic reference systems are characterized using X-ray diffraction, X-ray photoelectron, and UV–vis spectroscopies, together with microscopy and porosimetry tools. Such characterization was able to show the formation of PtPd alloy particles in the bimetallic catalysts. The mono and bimetallic TiO2-based powders were tested in the photo-production of hydrogen from methanol:water mixtures under UV and visible illumination conditions. Analysis of catalytic properties was carried out through the measurement of the optical properties of the materials and the calculation of the true quantum efficiency parameter. Results indicate that the PtPd co-catalysts have superior performance that the Pt and Pd monometallic counterparts both under UV and visible illumination conditions. Optimum performance was achieved with a material having a Pt:Pd 1:1 atomic ratio. A remarkable increase in the use of the visible range and thus in sunlight utilization is achieved with the 1:1 Pt:Pd bimetallic system with respect to the monometallic counterparts. The evolution of the bimetallic co-catalysts under reaction conditions as well as their key properties to interpret photo-activity were analyzed with the help of the above mentioned techniques as well as photoluminescence spectroscopy and an in-situ infrared analysis of the materials under reaction conditions. Results point out the critical role that both PtPd alloying and the metal-support interface play in the reaction.

Efficient catalysts of supported PtPd nanoparticles on 3D ordered macroporous TiO2 for soot combustion: Synergic effect of Pt-Pd binary components

The efficient nanocatalyst of three-dimensionally ordered macroporous (3DOM) TiO2-supported Pt-Pd nanoparticles (PtPd/3DOM-TiO2) was easily fabricated by method of the gas bubbling-assisted membrane reduction (GBMR). The catalyst shows well-defined ordered macroporous nanostructure with the average pore size of 280 nm, and hemispherical PtPd nanoparticles (NPs) with mean particle size of 3.6 nm are well dispersed and deposited on the inner walls of 3DOM-TiO2 support. 3DOM nanostructure can improve the contact efficiency between soot particles and catalysts, and enhances the mass transfer of soot particles through the porous catalysts. The synergic effect of Pt-Pd binary components is favorable for enhancing the intrinsic redox property originated from the strong metal (PtPd)-support (TiO2) interaction (SMSI). Remarkably, PtPd/3DOM-TiO2 catalyst exhibits highest catalytic activity for diesel soot combustion in comparison with those of supported single Pt or Pd NPs, i.e., its values of T10, T50 and T90 are only 262, 338 and 386 °C, respectively. And the TOFPtPd value of PtPd/3DOM-TiO2 catalyst (1.27 × 10−3 S−1) is 4.3 times as much as that of Pd/3DOM-TiO2 catalyst (0.29 × 10−3 S−1). In addition, PtPd/3DOM-TiO2 catalyst shows the good stability of activity and nanostructure during five cycles of soot-TPO tests. The ternary catalyst of 3DOM TiO2-supported uniform Pt-Pd alloy NPs can not only decrease the usage amount of Pt, but also is potential to practical application in catalytic combustion of diesel soot particles.

Monodispersed PtPdNi Trimetallic Nanoparticles-Integrated Reduced Graphene Oxide Hybrid Platform for Direct Alcohol Fuel Cell

The direct alcohol fuel cell has recently emerged as an important energy conversion device. In the present article, superior alcohol (ethanol, ethylene glycol, and glycerol) electrooxidation performance using trimetallic platinum–palladium–nickel (PtPdNi) alloy nanoparticles of diameters from 2–4 nm supported on a reduced graphene oxide (rGO) electrocatalyst is demonstrated. A simple and single-step solvothermal technique is adopted to fabricate the alloy/rGO hybrid electrocatalysts by simultaneous reduction of metal ions and graphene oxide. The detailed electrochemical investigation revealed that the performance of the trimetallic/rGO hybrid toward electrooxidation of different alcohols is higher than that of bimetallic alloy/rGO hybrids and the state-of-the-art Pt/C catalyst. The incorporation of Ni into the PtPd alloy is found to change the surface of the electronic structure PtPd alloy leading to higher electrochemical surface areas and improved kinetics. In addition, the hydrophilic nature of Ni not ...

Metal coated and nanofiller doped polycarbonate membrane for hydrogen transport

The modification in the polymeric membrane combined with metallic film as well as composites with inorganic nanofiller can be used for separation of various gases, with hydrogen gas as it is widely used as fuel material. The change in free volume due to modification in polymer chains alters the transport mechanism. In this work, the transport behaviour of H2 across the different metal coated and nanocomposite membrane has been studied and compared with that of standard polycarbonate membrane. Transport properties changes due to the modification in the composition of nanofiller. A PtPd alloy thin film and iridium thin film of around 8–10 nm was coated on polycarbonate substrate using sputtering technique to make layered polymer nanocomposite membrane. Moreover, SiO2 nanocomposites with 10 wt% and 15 wt % were prepared by solution casting method and the uniform dispersion of silica nanoparticles was obtained by sonication before casting the membrane. Further, the tests were carried at constant upstream pressure 30 psi and at constant temperature 35 °C using constant volume/variable pressure method.

Synthesis of Pt-M (M=Ir, Pd) Bimetallic Nanocrystals with Controlled Shape and Composition As a High-Performance Electrocatalyst for Ammonia Electrolysis

Ammonia is a promising hydrogen storage carrier owing to its higher hydrogen capacity relative to liquid hydrogen (108 vs 71 g/L), non-flammability, well-developed technologies for synthesis and distribution.1-2 To utilize ammonia as the hydrogen storage carrier, it is essential to develop a highly efficient and durable catalyst that decomposes ammonia into hydrogen and nitrogen. Platinum (Pt) is the most effective catalyst for the electrolysis of ammonia, but it is rapidly deactivated during the reaction due to the strong adsorption of nitrogen on the surface. Thus, it is critical to develop a highly efficient and robust catalyst that surpasses Pt catalyst, enabling the utilization of ammonia as a safe and efficient hydrogen storage carrier. In this work, we synthesized nano-sized Pt-Ir (and Pt-Pd) alloy cubes as a high-performance electrocatalyst for ammonia electrolysis. During the synthesis, both elemental composition and shape of nanocrystals were systemically controlled for improving their electrocatalytic performance (Fig. 1a). Among the as-synthesized catalysts, the Pt-Ir nanocubes exhibited ~7.2 and ~4.6 times higher specific (mA/cm2) and mass (A/mg) activities, respectively, relative to a state-of-the-art commercial Pt/C catalyst (Tanaka) at 0.6 V (vs RHE, Fig. 1b). The significantly enhanced activity can be attributed to reduced adsorption strength of nitrogen, thus mitigating the deactivation of active sites of the catalyst. Hanada, N.; Hino, S.; Ichikawa, T.; Suzuki, H.; Takai, K.; Kojima, Y., Hydrogen generation by electrolysis of liquid ammonia. Chem Commun 2010, 46 (41), 7775-7777.Vitse, F.; Cooper, M.; Botte, G. G., On the use of ammonia electrolysis for hydrogen production. Journal of Power Sources 2005, 142 (1), 18-26. Figure 1

Silsesquioxane stabilized platinum-palladium alloy nanoparticles with morphology evolution and enhanced electrocatalytic oxidation of formic acid

Bimetallic catalysts have attracted enormous attention with their enhanced electrocatalytic properties in fuel cells. Herein a series of silsesquioxane (POSS) stabilized platinum-palladium (PtPd) alloy nanoparticles (NPs) with morphology evolution were facilely synthesized with the co-chemical reduction using formaldehyde as the reductant. By varying the ratio of Pt to Pd, the PtPd alloy NPs evolved from truncated octahedrons to octahedrons, and triangular nanoplates. The mechanism of morphology evolution is that Pt and Pd could self-assemble on POSS to form PtxPd1−x intermediates with different Pt/Pd ratios. In addition, formaldehyde could selectively bind to the {1 1 1} facets of Pd to control the growth rates of different facets and help PtxPd1−x intermediates with different Pt/Pd ratio grow into different morphology of PtxPd1−x alloys. The morphology tuning endowed the PtPd alloy NPs superior performance for formic acid electrooxidation. Compared with Pt, Pd NPs, and commercial Pt/C catalyst, the PtPd alloy NPs displayed larger electrochemically active surface area, enhanced electrocatalytic activity and durability toward oxidation of formic acid, and increased CO tolerance. This work suggested that modification of catalytic activity through morphology tuning with composition adjustment might provide some new pathways for the design of promising catalysts with advanced performance.

Composition-controlled synthesis of platinum and palladium nanoalloys as highly active electrocatalysts for methanol oxidation

Platinum and palladium (PtPd) alloy nanoparticles (NPs) are excellent catalysts for direct methanol fuel cells. In this study, we developed PtPd alloy NPs through the co-reduction of K2PtCl4 and Na2PdCl4 in a polyol synthesis environment. During the reaction, the feed molar ratio of the two precursors was carried over to the final products, which have a narrow size distribution with a mean size of approximately 4 nm. The catalytic activity for methanol oxidation reactions possible depends closely on the composition of as-prepared PtPd alloy NPs, and the NPs with a Pt atomic percentage of approximately 75% result in higher activity and stability with a mass specific activity that is 7 times greater than that of commercial Pt/C catalysts. The results indicate that through composition control, PtPd alloy NPs can improve the effectiveness of catalytic performance.