Pt-Ru Bimetallic Catalysts Research Articles

Synergistic catalysis in loaded PtRu alloy nanoparticles to boost base-free aerobic oxidation of 5-hydroxymethylfurfural

The synergistic catalysis of dual metal sites is vital for selective activation of complicated chemical bonds in biomass compounds. The base-free selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) using air as oxidant and water as solvent is a highly sustainable upgrading process for cellulosic carbohydrates. In this work, a series of PtxRu-MgAlO (x = 0.5, 1, 2 and 3, in mole) nanocatalysts with controlled particle sizes (ca. 2 nm) were synthesized by a PVP-assisted adsorption method. The Pt2Ru-MgAlO catalyst showed 99% selectivity of FDCA with full conversion of HMF at only 100 °C under 0.2 MPa of air. In the meantime, an initial reaction rate of HMF of 2.8 mmol molM−1 s−1 and an intrinsic turnover frequency of 61.5 h−1 were attained, respectively. Besides, this catalyst exhibited superior stability during five consecutive reuses without metal leaching. It was disclosed that the Pt-Ru interaction played critical roles in determining the intrinsic activity and the CO bond activation of the prepared PtxRu-MgAlO catalysts. Kinetic experiments combined with in situ chemisorption techniques clearly unraveled adsorption and activation processes of CO bond on Pt0-Ru0 sites. To the best of our knowledge, this work firstly reported a PtRu bimetallic catalyst for aerobic oxidation of HMF and provided insight into synergistic catalysis.

Electrocatalysis as an efficient alternative to thermal catalysis over PtRu bimetallic catalysts for hydrogenation of benzoic acid derivatives

PtRu bimetallic nanoclusters electrodeposited on carbon paper catalysts show highly efficient and uniquely selective electrocatalytic hydrogenation of aromatic rings in benzoic acid derivatives under mild and environmentally-friendly conditions.

Effects of preparation method on exsolution and alloy formation in a PtRu bimetallic catalyst for hydrogen production via diesel reforming: Impregnation versus combustion synthesis

In diesel reforming, a catalyst is easily deteriorated by thermal sintering and coke formation. A proper preparation method improves stability by modifying the physicochemical properties of the catalyst. In this paper, the effects of preparation methods on exsolution and alloy formation in PtRu bimetallic catalysts for diesel reforming were studied. The catalysts were prepared by impregnation and combustion synthesis. The structure, surface morphology, and reduction characteristics of each catalyst were characterized by XRD, STEM, and H2-TPR. Based on these characterizations, the behavior of each catalyst in the reforming environment was identified by comparison of properties observed before and after the reaction. Pt and Ru individually crystallized from the impregnated catalyst, whereas Pt and Ru exsolved from the combustion synthesis catalyst to form a PtRu alloy. As a result, the combustion synthesis catalyst showed higher stability and coke resistance than the impregnated catalyst.

Theoretical insights into effect of surface composition of Pt-Ru bimetallic catalysts on CH3OH oxidation: mechanistic considerations

A deeper mechanistic understanding on CH3OH oxidation on Pt-Ru alloys with different Ru surface compositions is provided by DFT-based theoretical studies in this paper. The present results show that alloying and surface compositions of Ru can change CH3OH oxidation pathway and activity. The optimal surface composition of Ru is speculated to be ca. 50% since the higher Ru surface composition can lead to formation of carbonaceous species that can poison surface. Our present calculated Ru surface composition of ca. 50% exhibits excellent consistency with experimental studies. The origin of enhanced catalytic activity of Pt-Ru alloys is determined. The significantly decreased surface work functions after alloying suggest more electrons are transferred into adsorbates. The calculated lower electrode potentials after alloying imply that lower overpotentials are required for CH3OH oxidation. The excellent consistency with experimental study on decreased onset potentials after alloying further confirms accuracy of our present calculated results. It is hoped that a systematic understanding of the atomic- and molecular-level processes on CH3OH oxidation mechanisms on Pt-Ru alloys will result in the ultimate goal of the explanation of origin of enhanced electrocatalytic activity and design of improved Pt-based alloy electrocatalysts for DMFCs.

Synergistic effects of bimetallic PtRu/MCM-41 nanocatalysts for glycerol oxidation in base-free medium: Structure and electronic coupling dependent activity

Bimetallic PtRu catalyst was first reported for oxidation of glycerol to glyceric acid in base-free medium using O2 as the oxidant. A combination of density functional theory (DFT) calculations and multi-characterizations (e.g., H2-TPR, HAADF-STEM and XPS) revealed that the strong interaction between Pt and Ru could promote the dispersion of PtRu alloy nanoparticles and enhance the electronic coupling effect on the metal surface. Meanwhile, compared to the monometallic Pt catalyst, the introduction of Ru contributes to the direct dissociation of molecular oxygen and water to hydroxyl group, leading to the excellent catalytic activity. A volcanic-shaped relationship between Ru/Pt ratio, catalytic performance, structure-sensitivity and electronic coupling effect was systematically established. Furthermore, the role of structure-sensitivity and electronic coupling effect for the enhanced catalytic activity of PtRu catalysts with different Ru/Pt ratios are distinguished in detail. Finally, the Pt0.8Ru0.8/MCM-41 catalyst showed excellent catalytic activity (TOF: 823.9 h−1), glyceric acid selectivity (80.1%) and stability (recycling for 5th) under the optimized conditions (80 °C, 1 MPa O2 and 12 h). The insights and methodology reported here may pave the way to the rational design of bimetallic catalysts for efficient conversion of bio-derived substrates under mild conditions.

Unraveling the composition-activity relationship of Pt[sbnd]Ru binary alloy for hydrogen oxidation reaction in alkaline media

The research and development of hydrogen oxidation reaction catalysts in alkaline media is a prerequisite for the commercialization of alkaline polymer electrolyte fuel cell. PtRu bimetallic catalyst was found to be more active towards HOR than Pt in alkaline, but the composition-activity relationship of PtRu alloys is still lacking. Herein, a series of PtRu alloy planar electrodes with 14 different compositions were prepared in a high-throughput fashion using an improved magnetron sputtering method. The atomic ratio of Pt was controlled from 6.7% to 99.7% within the samples. The corresponding electro-catalytic activities towards the HOR in alkaline were systematically measured by rotating disc electrode method. A volcano-shape relationship between the HOR exchange current density and the Ru atomic fraction was revealed, and maximum activity was observed at ca. 55% content of Ru. The enhancement in electro-catalytic activity is attributed to a reduction in the electronic charge density of Pt upon Ru doping.

Synthesis and characterization of bimetallic catalysts Pd-Ru and Pt-Ru supported on γ-alumina and zeolite FAU for the catalytic transformation of HMF

It is well known the effects and limitations of the use of fossil fuels, for that reason is necessary to establish alternative sources of energy. The 5-hydroxymethylfurfural (HMF) is a chemical compound that can be obtained from the carbohydrates present in the biomass. Is a key compound for the obtaining of several valuable chemicals, many of them have a promising application as biofuels. In the present work, Pd-Ru and Pt-Ru bimetallic catalysts with low metal content (0.5%) supported on commercial γ-Al2O3 and FAU zeolite prepared by hydrothermal method, were synthesized and characterized to transform HMF into valuable chemicals under mild reaction conditions. Two crystallographic phases were found to coexist in the zeolite synthesized as support, the FAU phase prevailing over the LTA when calcined at 550 °C. The system studied with formic acid as hydrogen donor, under mild reaction conditions, showed a partial hydrogenation of HMF molecule evidenced in the 5-MF and 2,5-DMF formation. Also, a partial oxidation and esterification is happening for the formation of 2,5-DFF and 5-A-2-F, respectively. The catalysts supported on FAU showed better conversion of HMF that catalysts supported on γ-Al2O3. Although all metals showed catalytic activity by separed, Pd-Ru combination was more selective to produce 5-MF, 2,5-DMF and 2,5-DFF than Pt-Ru combination, and showed production of valuable furan derivatives even in their second and thir use. Pd–Ru/FAU catalyst formed a PdRu alloy phase, which can be related to its better catalytic performance.

Preparation and Evaluation of Pt-Ru/CNTs Catalysts for Direct Methanol Fuel Cell

The most widely used electro-catalyst material in direct methanol fuel cell (DMFCs) are Pt-Ru bimetallic electro-catalysts, which show the best performance among other bimetallic catalysts. Many methods exist to prepare catalysts with bimetallic surfaces, and the properties and performance of these catalysts vary widely. Previous studies have shown that combining strong electrostatic adsorption (SEA) and electroless deposition (ED) methods can increase the surface area of the Pt particles by lowering the particle sizes of the bimetallic particles [1]; however, decreasing particle sizes can result in other problems such as thermal stability. Therefore, new routes for development of highly active and stable catalyst supports have become important to study. Among the different forms of carbon support, carbon nanotubes (CNTs) are especially known for their crystallinity which not only imparts structural uniformity and high electrical conductivity, but also assures stability of the nanomaterials deposited on the support. In addition, they fulfill the properties of high surface area, high thermal conductivities, extraordinary strength, and resilience to an acidic environment, all of which can prove highly important for improving the performance of a fuel cell catalyst. In this work we have investigated the effect of CNTs support for the methanol electro-oxidation reaction. The combination of SEA and ED methods have been used for deposition of Pt-Ru bimetallic catalysts on CNTs and to predict the effect of support on DMFC performance. The materials synthesized will be characterized by X-ray diffraction (XRD) spectroscopy for crystal structure and energy dispersive spectroscopy (EDS) will be employed to examine elemental analysis and distribution. To observe surface morphology HRTEM images will be used, and BET surface areas and pore volume measurements will be carried out to evaluate porosity and pore size distributions. References Tengco, J.M.M., et al., Synthesis and Electrochemical Evaluation of Carbon Supported Pt-Co Bimetallic Catalysts Prepared by Electroless Deposition and Modified Charge Enhanced Dry Impregnation. Catalysts, 2016. 6(6).

Mechanistic Study of the Hydrogen Oxidation/Evolution Reaction over Bimetallic PtRu Catalysts

In this work, the activity of bimetallic PtRu/C with varying amounts of Ru for the hydrogen oxidation/evolution reactions (HOR/HER) was determined. The results demonstrate that surface Ru is not necessary for high activity, which shows that the improved activity of the bimetallic PtRu comes from the electronic interaction of Ru with Pt and the tuning of the hydrogen binding energy (HBE). Using the charge transfer coeffiecient from Butler-Volmer fitting and kinetic modeling, it was determined that Ru affects the HOR/HER mechanism in two ways: changing the pathway from Tafel-Volmer to Heyrovsky-Volmer, and lowering of the activation barrier of the Volmer step. Utilizing catalysts with Heyrovsky-Volmer(RDS) mechanism as well as focusing on tuning the HBE might help improve the activity of non-precious metal catalysts; allowing PGM-free fuel cells to become economically viable.

Mechanistic and kinetic insights into the Pt-Ru synergy during hydrogen generation from ammonia borane over PtRu/CNT nanocatalysts

Increasing the utilization efficiency of noble metals by the synergy with less expensive metals is an important yet challenging issue in heterogeneous catalysis. Herein, exemplified with Pt-catalyzed hydrolytic dehydrogenation of ammonia borane, partial substitution of the Pt catalysts by over 11 times less expensive Ru is studied to obtain highly efficient and cost-effective Pt-based catalysts. It is observed that the Pt-Ru bimetallic catalysts, especially Pt0.5Ru0.5/CNT, deliver higher hydrogen generation activity and durability than the Pt/CNT and Ru/CNT catalysts, indicating a remarkable Pt-Ru synergy. The underlying nature of this synergy is elucidated by combining kinetic and isotopic analyses with multiple techniques such as HAADF-STEM, EDX, XRD, H2-TPR, HRTEM, XPS and ICP-AES. The appropriate activation energy and entropy of activation for the reaction are mainly responsible for the highly active Pt0.5Ru0.5/CNT catalyst, and a volcano-shaped relationship for the reactivity of these five catalysts as a function of entropy of activation is proposed. The insights revealed here might guide the rational design of catalysts for this reaction, and the methodology could be extended to unravel the nature of other bi- or multi-metallic catalysts.

Effect of pH on the Activity of Hydrogen Oxidation Reaction/Hydrogen Evolution Reaction over PtRu Bimetallic Catalysts

Hydrogen proton exchange membrane fuel cell (PEMFC) powered automobiles have become commercially available, but are still too expensive. Hydroxide exchange membrane fuel cells (HEMFCs) offer the possibility of cheaper non-precious metal catalysts. However, the hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) are significantly slower in base than in acid for Pt, Pd, Ir, and Rh1-4. PtRu shows higher HOR/HER activity than Pt5, 6, so understanding the mechanism of the HOR/HER on PtRu is key to developing non-precious metal catalysts for HEMFCs. Using the rotating disk electrode, bimetallic PtRu showed a minimum in the HOR/HER activity, pH relationship (Figure 1). The hydrogen binding energy and the hydroxide binding energy measured from the hydrogen underpotential desorption peak and the CO stripping peak, respectively, did not change significantly with pH. Leaching Ru from the catalyst, it was found that the HOR/HER activity of PtRu remains approximately constant while the Ru content is reduced. When a small amount of Ru is leached from the surface, the activity increases and only after a significant amount of Ru has been removed from the surface/near surface of the catalyst does the activity change. This suggests that the HOR mechanism is not the bifunctional mechanism. The charge transfer coefficient, α, decreases with the Ru content going from 0.8 to 0.5. Fitting the kinetic data with the dual pathway model7 shows that below pH 11, the Heyrovsky and Volmer reaction barriers are comparable and above pH 11, the Volmer step becomes rate determining. It is proposed that Ru can align more oxygen species on the surface giving water a more favorable orientation for the Volmer step to proceed, which results in an increase in activity.

Effect of Valency of Sn in Sn-Modified Pt-Ru Catalyst on CO Tolerance and HOR Activity for PEFC

Bimetallic Pt-Ru catalysts and addition of SnO2 to the carbon support have been shown to enhance CO tolerance for polymer electrolyte fuel cells (PEFCs). We have investigated the effect of valency of Sn in Sn-modified Pt-Ru catalyst on CO tolerance and hydrogen oxidation reaction (HOR) activity. During a rapid quenching method for catalyst preparation, Pt-Ru-Sn/C and Pt-Ru/SnO2/C were treated in H2 and He at 880 oC, respectively. Without CO contamination, the terminal voltage of the cell using Pt-Ru-Sn/C is lower than those using Pt-Ru/SnO2/C or commercial Pt-Ru/C (TKK, TEC61E54). In the presence of 1000-ppm CO contamination, the terminal voltage of the cell using Pt-Ru/SnO2/C is the highest, followed by Pt-Ru-Sn/C and Pt-Ru/C (TKK, TEC61E54). It is concluded that Sn in the Pt-Ru-Sn alloy reduces the HOR activity, while SnO2 does not. Both of metallic Sn in the Pt-Ru-Sn alloy and SnO2 encourage the CO tolerance.

Origin of Superior Activity of Ru@Pt Core-Shell Nanoparticles towards Hydrogen Oxidation in Alkaline Media

Platinum shows an exceptionally high activity for the hydrogen oxidation reaction (HOR) in acidic environment,[1] enabling ultra-low Pt-loadings on the anode side of proton exchange membrane fuel cells (PEMFCs).[2] Unlike in acid, this reaction is about two orders of magnitude slower on platinum and other platinum metals in alkaline electrolyte,[3]; [4] which has recently been suggested to be due to entropic effects.[5] Amongst other issues, the low HOR activity of Pt-based electrocatalysts in alkaline environment hinders the development of anion exchange membrane fuel cells (AEMFCs).[4] Bimetallic Pt-Ru catalysts were demonstrated to exhibit significantly higher HOR activities in acid[6]; [7] and base[8]–[10] compared to Pt catalysts. One hypothesis for the high HOR activity of Pt-Ru alloys in base is a bi-functional mechanism,[9]; [10] with hydrogen being adsorbed on Pt and hydroxide being supplied by more oxophilic Ru, whereby the presence of hydroxide in the vicinity of Pt-Hads would accelerate the rate of the hydrogen oxidation. The second hypothesis considers a modification of the electronic structure of platinum by ruthenium,[8] leading to a lower Pt-Hads binding energy and ultimately to a higher activity of platinum towards the oxidation of hydrogen. While the exposure of ruthenium on the surface of the catalyst is absolutely mandatory for a bi-functional mechanism, this is not the case for an activity enhancement due to a modification of the electronic structure of platinum. Based on this fundamental difference, we have attempted to identify the actual HOR mechanism on bimetallic Pt-Ru catalysts by evaluating Ru@Pt core-shell nanoparticles with various Pt-coverages and shell thicknesses. Pt-coverage and shell thickness were determined electrochemically via the Ru-oxide reduction peak and COads stripping voltammetry, a method established by El Sawy et al.[11] Considering a pure, bi-functional mechanism where hydroxide on Ru reacts with Hads on Pt, ruthenium is required to be on the surface of the catalytically active particle. Hence, we expect the highest activity at submonolayer Pt-coverage. For the bifunctional mechanism, covering the whole Ru-surface with Pt would result in a performance equal or similar to that of pure Pt (s. red line in Fig. 1). In contrast to that, for a purely electronic effect, Ru surface atoms would not be required for effective HOR catalysis and one would expect the best performing Ru@Pt catalysts to have a fully Pt-covered Ru surface or even multilayers of Pt; the optimum Pt-shell thickness would mainly depend on the range of the electronic effect (s. black line in Fig. 1). Based on this concept, we will present data to disentangle the mechanism of the hydrogen oxidation on bimetallic Pt-Ru catalysts. The activity of the developed catalysts will be compared to Pt catalysts prepared by the same method with a similar particle size as that of the Ru@Pt core-shell nanoparticles. Acknowledgment The authors of this work thank the microanalytical laboratory at TUM for quick and reliable elemental analysis. References 1 J. Durst; C. Simon; F. Hasche and H. A. Gasteiger, J. Electrochem. Soc., 1, F190-F203 (2015). 2 H. A. Gasteiger; J. E. Panels and S. G. Yan, J. Power Sources, 1-2, 162 (2004). 3 P. J. Rheinlander; J. Herranz; J. Durst and H. A. Gasteiger, J. Electrochem. Soc., 14, F1448–F1457 (2014). 4 W. Sheng; H. A. Gasteiger and Y. Shao-Horn, J. Electrochem. Soc., 11, B1529 (2010). 5 J. Rossmeisl; K. Chan; E. Skúlason; M. E. Björketun and V. Tripkovic, Catalysis Today, 36 (2016). 6 J. X. Wang; Y. Zhang; C. B. Capuano and K. E. Ayers, Scientific reports, 12220 (2015). 7 J. X. Wang; P. He; Y. Zhang and S. Ye, ECS Transactions, 3, 121 (2014). 8 K. Elbert; J. Hu; Z. Ma; Y. Zhang; G. Chen; W. An; P. Liu; H. S. Isaacs; R. R. Adzic and J. X. Wang, ACS Catal., 11, 6764 (2015). 9 S. St. John; R. W. Atkinson; R. R. Unocic; T. A. Zawodzinski and A. B. Papandrew, J. Phys. Chem. C, 24, 13481 (2015). 10 Y. Wang; G. Wang; G. Li; B. Huang; J. Pan; Q. Liu; J. Han; L. Xiao; J. Lu and L. Zhuang, Energy Environ. Sci., 1, 177 (2015). 11 El Sawy, Ehab N.; H. A. El-Sayed and V. I. Birss, Chem. Commun., 78, 11558 (2014). Figure 1

Origin of Superior Activity of Ru@Pt Core-Shell Nanoparticles towards Hydrogen Oxidation in Alkaline Media

There is an ongoing discussion about the nature of the high hydrogen oxidation reaction (HOR) activity of bimetallic Pt-Ru catalysts in alkaline media. We provide an insight on the HOR mechanism for this type of catalyst, excluding bifunctionality as the main driving force for the oxidation of hydrogen. In order to do so, we prepared and evaluated Ru@Pt core-shell nanoparticles with sub-, mono- and multilayered Pt-shells. Rotating disk electrode (RDE) studies in 0.1 M NaOH solution of all prepared catalysts, including Pt/C as a reference show that Ru particles fully encapsulated with a Pt-shell show significantly higher activity than Ru particles that are solely covered with Pt-submonolayers. Furthermore, we found a 4-fold enhancement of Ru@Pt vs. pure Pt with respect to the surface normalized HOR activity. The Ru@Pt catalysts were characterized by COads-stripping voltammetry, as well as cyclic voltammetry (CV) in order to identify the Pt-coverage and shell thickness.

IrO2 as a promoter of Pt-Ru for methanol electro-oxidation.

A multifunctional catalyst may represent a valid route to enhance methanol electro-oxidation. Ternary catalysts based on Pt modified with both Ru and Ir oxides show better performance for methanol electro-oxidation than bi-metallic Pt-Ru catalysts.

Nanoporous Platinum Electrodes as Substrates for Metal Oxide-Supported Noble Metal Electrocatalytic Nanoparticles: Synergistic Effects During Electrooxidation of Ethanol

Electrocatalytic oxidation of ethanol in acid medium (0.5 mol dm–3 H2SO4) was significantly enhanced by not only supporting bimetallic PtRu nanoparticles on nanostructured metal oxides (TiO2 or WO3), but also by depositing such catalytic systems on planar nanoporous platinized electrode substrates. Incorporation of TiO2 or WO3 into the electrocatalytic interface was likely to improve proton mobility and to provide –OH groups capable of inducing the removal of poisoning species, such as CO, from the Pt sites in the bimetallic PtRu catalyst. Synergistic interactions between ruthenium and titania were also possible. Regularly porous nanostructured platinum substrate also permitted development of submicro ‘reactors’ where reactant molecules, electrolyte ions, and all active components (TiO2 or WO3, Pt substrate, PtRu catalytic sites) could co-exist and become easily accessible. While WO3 was able to undergo fast reversible redox transitions to non-stoichiometric oxides, efficient utilization of inert (non-electroactive) TiO2 required admixing with carbon nanotubes to ensure easy charge distribution and good conductivity at the electrocatalytic interface.

In Situ Ru K-Edge X-ray Absorption Spectroscopy Study of Methanol Oxidation Mechanisms on Model Submonolayer Ru on Pt Nanoparticle Electrocatalyst

In situ X-ray absorption spectroscopy (XAS) with electrochemical reaction control has enabled a detailed investigation of the mechanism of the methanol electrooxidation by a bimetallic PtRu catalyst. By the use of an original electrodeposition technique, ca. 0.3 monolayer of Ru was deposited on the surface of unsupported Pt nanoparticles (Ru@Pt). The presence of Ru atoms only at the surface of nanoparticles turns a bulk sensitive XAS technique into a surface methodology which permits correlation of the X-ray absorption fine structure at the Ru K-edge to the role of Ru atoms in the methanol oxidation process. In situ XAS spectra of the Ru@Pt nanoparticles were collected at various electrode potentials in background electrolyte, and then in 1 M solution of methanol (CH3OH) in the same electrolyte. Significant differences in the catalyst state have been revealed between these two environments. In the background electrolyte, Ru gradually oxidizes from mostly metallic to a Ru(III)/Ru(IV) mixture at the highest potentials. In the presence of CH3OH, the Ru oxidation state remains a mixture of metallic and Ru(III) even at the highest potentials. CO-type species were found adsorbed on Ru atoms at all potentials and coadsorbed with OH species at potentials 0.175 V vs Ag/AgCl and higher with steady number of near neighbors. The same potential correlates to the beginning of methanol oxidation reaction observed electrochemically. Therefore coadsorption of CO and OH groups on Ru atoms appears to be critical in the methanol oxidation process. The need for OH groups for CO removal from Pt sites was previously suggested by the bifunctional CH3OH oxidation mechanism; however, occupancy of Ru atoms with CO species and direct structural observations of the coadsorption of CO and OH on the same Ru atom is a novel finding resulting from this study. Other changes in the catalyst environment were observed, including decreased Ru–Ru and Ru–Pt bond distances, increased numbers of Ru–Pt near neighbors, and decreased number of Ru–Ru near neighbors.

ChemInform Abstract: Synthesis and Applications of Carbon Nanotubes‐Supported PtRu Bimetallic Catalysts: A Mini‐Review

AbstractReview: 65 refs.

Synergistic effect in heterogeneously catalyzed reduction of U(VI) and Np(V) and decomposition of hydrazine and oxalic acid with bimetallic Pt-Ru catalysts

Synergistic effect in heterogeneously catalyzed reduction of U(VI) and Np(V) and decomposition of hydrazine and oxalic acid with bimetallic Pt-Ru catalysts

Synthesis and Applications of Carbon Nanotubes-Supported PtRu Bimetallic Catalysts: A Mini-Review

Bimetallic nanoparticles have been recently used for heterogeneous and electrochemical catalysts. Carbon nanotubes are promising support for the catalysts because of their excellent chemical stability, large surface area and good thermal and electrical conductivities. This work briefly summarizes recent results published in literature and patents for the synthesis and applications of carbon nanotube-supported PtRu bimetallic catalysts. Keywords: Carbon nanotubes, bimetallic catalyst, fuel cells, heterogeneous catalysis, patent, PtRu nanoparticles, PtRu supported CNTs