The Experts below are selected from a list of 54654 Experts worldwide ranked by ideXlab platform
Masashi Nakamura - One of the best experts on this subject based on the ideXlab platform.
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Effect of hydrophobic cations on the Oxygen Reduction Reaction on single‒crystal platinum electrodes
Nature Communications, 2018Co-Authors: Tomoaki Kumeda, Nagahiro Hoshi, Hiroo Tajiri, Osami Sakata, Masashi NakamuraAbstract:Highly active catalysts for the Oxygen Reduction Reaction are essential for the widespread and economically viable use of polymer electrolyte fuel cells. Here we report the Oxygen Reduction Reaction activities of single‒crystal platinum electrodes in acidic solutions containing tetraalkylammonium cations with different alkyl chain lengths. The high hydrophobicity of a tetraalkylammonium cation with a longer alkyl chain enhances the Oxygen Reduction Reaction activity. The activity on Pt(111) in the presence of tetra‒n‒hexylammonium cation is eight times as high as that without this cation, which is comparable to the activities on Pt3Co(111) and Pt3Ni(111) electrodes. Hydrophobic cations and their hydration shells destabilize the adsorbed hydroxide and adsorbed water. The hydrophobic characteristics of non‒specifically adsorbed cations can prevent the adsorption of poisoning species on the platinum electrode and form a highly efficient interface for the Oxygen Reduction Reaction.Highly active catalysts for the Oxygen Reduction Reaction are valuable for fuel cells. Here the authors evaluate catalytic activity of single-crystal platinum electrodes in acidic solutions that contain hydrophobic cations, which prevent the adsorption of poisoning species and form an efficient interface.
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Effect of hydrophobic cations on the Oxygen Reduction Reaction on single‒crystal platinum electrodes.
Nature communications, 2018Co-Authors: Tomoaki Kumeda, Nagahiro Hoshi, Hiroo Tajiri, Osami Sakata, Masashi NakamuraAbstract:Highly active catalysts for the Oxygen Reduction Reaction are essential for the widespread and economically viable use of polymer electrolyte fuel cells. Here we report the Oxygen Reduction Reaction activities of single‒crystal platinum electrodes in acidic solutions containing tetraalkylammonium cations with different alkyl chain lengths. The high hydrophobicity of a tetraalkylammonium cation with a longer alkyl chain enhances the Oxygen Reduction Reaction activity. The activity on Pt(111) in the presence of tetra‒n‒hexylammonium cation is eight times as high as that without this cation, which is comparable to the activities on Pt3Co(111) and Pt3Ni(111) electrodes. Hydrophobic cations and their hydration shells destabilize the adsorbed hydroxide and adsorbed water. The hydrophobic characteristics of non‒specifically adsorbed cations can prevent the adsorption of poisoning species on the platinum electrode and form a highly efficient interface for the Oxygen Reduction Reaction.
Tomoaki Kumeda - One of the best experts on this subject based on the ideXlab platform.
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Effect of hydrophobic cations on the Oxygen Reduction Reaction on single‒crystal platinum electrodes
Nature Communications, 2018Co-Authors: Tomoaki Kumeda, Nagahiro Hoshi, Hiroo Tajiri, Osami Sakata, Masashi NakamuraAbstract:Highly active catalysts for the Oxygen Reduction Reaction are essential for the widespread and economically viable use of polymer electrolyte fuel cells. Here we report the Oxygen Reduction Reaction activities of single‒crystal platinum electrodes in acidic solutions containing tetraalkylammonium cations with different alkyl chain lengths. The high hydrophobicity of a tetraalkylammonium cation with a longer alkyl chain enhances the Oxygen Reduction Reaction activity. The activity on Pt(111) in the presence of tetra‒n‒hexylammonium cation is eight times as high as that without this cation, which is comparable to the activities on Pt3Co(111) and Pt3Ni(111) electrodes. Hydrophobic cations and their hydration shells destabilize the adsorbed hydroxide and adsorbed water. The hydrophobic characteristics of non‒specifically adsorbed cations can prevent the adsorption of poisoning species on the platinum electrode and form a highly efficient interface for the Oxygen Reduction Reaction.Highly active catalysts for the Oxygen Reduction Reaction are valuable for fuel cells. Here the authors evaluate catalytic activity of single-crystal platinum electrodes in acidic solutions that contain hydrophobic cations, which prevent the adsorption of poisoning species and form an efficient interface.
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Effect of hydrophobic cations on the Oxygen Reduction Reaction on single‒crystal platinum electrodes.
Nature communications, 2018Co-Authors: Tomoaki Kumeda, Nagahiro Hoshi, Hiroo Tajiri, Osami Sakata, Masashi NakamuraAbstract:Highly active catalysts for the Oxygen Reduction Reaction are essential for the widespread and economically viable use of polymer electrolyte fuel cells. Here we report the Oxygen Reduction Reaction activities of single‒crystal platinum electrodes in acidic solutions containing tetraalkylammonium cations with different alkyl chain lengths. The high hydrophobicity of a tetraalkylammonium cation with a longer alkyl chain enhances the Oxygen Reduction Reaction activity. The activity on Pt(111) in the presence of tetra‒n‒hexylammonium cation is eight times as high as that without this cation, which is comparable to the activities on Pt3Co(111) and Pt3Ni(111) electrodes. Hydrophobic cations and their hydration shells destabilize the adsorbed hydroxide and adsorbed water. The hydrophobic characteristics of non‒specifically adsorbed cations can prevent the adsorption of poisoning species on the platinum electrode and form a highly efficient interface for the Oxygen Reduction Reaction.
Vojislav R Stamenkovic - One of the best experts on this subject based on the ideXlab platform.
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Recent advances in the design of tailored nanomaterials for efficient Oxygen Reduction Reaction
Nano Energy, 2016Co-Authors: Haifeng Lv, Arvydas P. Paulikas, Dongguo Li, Dusan Strmcnik, Nenad M Markovic, Vojislav R StamenkovicAbstract:Abstract In the past decade, polymer electrolyte membrane fuels (PEMFCs) have been evaluated for both automotive and stationary applications. One of the main obstacles for large scale commercialization of this technology is related to the sluggish Oxygen Reduction Reaction that takes place on the cathode side of fuel cell. Consequently, ongoing research efforts are focused on the design of cathode materials that could improve the kinetics and durability. Majority of these efforts rely on novel synthetic approaches that provide control over the structure, size, shape and composition of catalytically active materials. This article highlights the most recent advances that have been made to tailor critical parameters of the nanoscale materials in order to achieve more efficient performance of the Oxygen Reduction Reaction (ORR).
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advanced platinum alloy electrocatalysts for the Oxygen Reduction Reaction
ACS Catalysis, 2012Co-Authors: Chao Wang, Nenad M Markovic, Vojislav R StamenkovicAbstract:In the past decade, significant advancement has been made in the development of electrocatalysts for energy conversion and storage. Among various approaches, alloying Pt with 3d transition metals has shown great potential in tailoring the atomic and electronic structures of catalytically active materials toward improved catalytic performance. Here, we provide a brief overview of the recent advancements in the design and synthesis of electrocatalysts for the Oxygen Reduction Reaction. Our focus is placed on the systematic studies of particle size, composition, and shape effect for the monodisperse and homogeneous platinum alloy electrocatalysts that have been synthesized by organic solution approaches.
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enhanced electrocatalysis of the Oxygen Reduction Reaction based on patterning of platinum surfaces with cyanide
Nature Chemistry, 2010Co-Authors: Dusan Strmcnik, Vojislav R Stamenkovic, Maria Escuderoescribano, Kensaku Kodama, Angel Cuesta, Nenad M MarkovicAbstract:The slow rate of the Oxygen Reduction Reaction in the phosphoric acid fuel cell is the main factor limiting its wide application. Here, we present an approach that can be used for the rational design of cathode catalysts with potential use in phosphoric acid fuel cells, or in any environments containing strongly adsorbing tetrahedral anions. This approach is based on molecular patterning of platinum surfaces with cyanide adsorbates that can efficiently block the sites for adsorption of spectator anions while the Oxygen Reduction Reaction proceeds unhindered. We also demonstrate that, depending on the supporting electrolyte anions and cations, on the same CN-covered Pt(111) surface, the Oxygen Reduction Reaction activities can range from a 25-fold increase to a 50-fold decrease. This behaviour is discussed in the light of the role of covalent and non-covalent interactions in controlling the ensemble of platinum active sites required for high turn over rates of the Oxygen Reduction Reaction.
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Monodisperse Pt3Co Nanoparticles as a Catalyst for the Oxygen Reduction Reaction: Size-Dependent Activity
Journal of Physical Chemistry C, 2009Co-Authors: Chao Wang, Kee-chul Chang, Jessica A Schlueter, Dennis Van Der Vliet, Dusan Strmcnik, Nenad M Markovic, Vojislav R StamenkovicAbstract:Monodisperse Pt3Co nanoparticles with size controlled from 3 to 9 nm have been synthesized through an organic solvothermal approach and applied as electrocatalysts for the Oxygen Reduction Reaction. Electrochemical study shows that the Pt3Co nanoparticles are highly active for the Oxygen Reduction Reaction and the activity is size-dependent. The optimal size for maximal mass activity was established to be around 4.5 nm by balancing the electrochemically active surface area and specific activity.
Nenad M Markovic - One of the best experts on this subject based on the ideXlab platform.
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Recent advances in the design of tailored nanomaterials for efficient Oxygen Reduction Reaction
Nano Energy, 2016Co-Authors: Haifeng Lv, Arvydas P. Paulikas, Dongguo Li, Dusan Strmcnik, Nenad M Markovic, Vojislav R StamenkovicAbstract:Abstract In the past decade, polymer electrolyte membrane fuels (PEMFCs) have been evaluated for both automotive and stationary applications. One of the main obstacles for large scale commercialization of this technology is related to the sluggish Oxygen Reduction Reaction that takes place on the cathode side of fuel cell. Consequently, ongoing research efforts are focused on the design of cathode materials that could improve the kinetics and durability. Majority of these efforts rely on novel synthetic approaches that provide control over the structure, size, shape and composition of catalytically active materials. This article highlights the most recent advances that have been made to tailor critical parameters of the nanoscale materials in order to achieve more efficient performance of the Oxygen Reduction Reaction (ORR).
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advanced platinum alloy electrocatalysts for the Oxygen Reduction Reaction
ACS Catalysis, 2012Co-Authors: Chao Wang, Nenad M Markovic, Vojislav R StamenkovicAbstract:In the past decade, significant advancement has been made in the development of electrocatalysts for energy conversion and storage. Among various approaches, alloying Pt with 3d transition metals has shown great potential in tailoring the atomic and electronic structures of catalytically active materials toward improved catalytic performance. Here, we provide a brief overview of the recent advancements in the design and synthesis of electrocatalysts for the Oxygen Reduction Reaction. Our focus is placed on the systematic studies of particle size, composition, and shape effect for the monodisperse and homogeneous platinum alloy electrocatalysts that have been synthesized by organic solution approaches.
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enhanced electrocatalysis of the Oxygen Reduction Reaction based on patterning of platinum surfaces with cyanide
Nature Chemistry, 2010Co-Authors: Dusan Strmcnik, Vojislav R Stamenkovic, Maria Escuderoescribano, Kensaku Kodama, Angel Cuesta, Nenad M MarkovicAbstract:The slow rate of the Oxygen Reduction Reaction in the phosphoric acid fuel cell is the main factor limiting its wide application. Here, we present an approach that can be used for the rational design of cathode catalysts with potential use in phosphoric acid fuel cells, or in any environments containing strongly adsorbing tetrahedral anions. This approach is based on molecular patterning of platinum surfaces with cyanide adsorbates that can efficiently block the sites for adsorption of spectator anions while the Oxygen Reduction Reaction proceeds unhindered. We also demonstrate that, depending on the supporting electrolyte anions and cations, on the same CN-covered Pt(111) surface, the Oxygen Reduction Reaction activities can range from a 25-fold increase to a 50-fold decrease. This behaviour is discussed in the light of the role of covalent and non-covalent interactions in controlling the ensemble of platinum active sites required for high turn over rates of the Oxygen Reduction Reaction.
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Monodisperse Pt3Co Nanoparticles as a Catalyst for the Oxygen Reduction Reaction: Size-Dependent Activity
Journal of Physical Chemistry C, 2009Co-Authors: Chao Wang, Kee-chul Chang, Jessica A Schlueter, Dennis Van Der Vliet, Dusan Strmcnik, Nenad M Markovic, Vojislav R StamenkovicAbstract:Monodisperse Pt3Co nanoparticles with size controlled from 3 to 9 nm have been synthesized through an organic solvothermal approach and applied as electrocatalysts for the Oxygen Reduction Reaction. Electrochemical study shows that the Pt3Co nanoparticles are highly active for the Oxygen Reduction Reaction and the activity is size-dependent. The optimal size for maximal mass activity was established to be around 4.5 nm by balancing the electrochemically active surface area and specific activity.
Jin Luo - One of the best experts on this subject based on the ideXlab platform.
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Design and electrochemical characterization of ternary alloy electrocatalysts for Oxygen Reduction Reaction
Journal of Electroanalytical Chemistry, 2013Co-Authors: Jin Luo, Jun Yin, Rameshwori Loukrakpam, Bridgid N. Wanjala, Bin Fang, Shiyao Shan, Lefu Yang, Ming Nie, Joshua KinzlerAbstract:Abstract The ability to engineer the composition and structure of nanoalloy catalysts is important for developing active, robust and low-cost catalysts for fuel cell applications. The recognition of the importance of structural and chemical alloying effects of nanoalloy particles on the electrocatalytic properties has been an important driving force for the exploration of various binary and ternary platinum-based alloy catalysts. In comparison with the extensive studies of binary alloy catalysts for Oxygen Reduction Reaction, the exploration of ternary nanoalloy catalysts in the past few years has led to many intriguing discoveries in terms of enhanced catalytic activities. In this article, we highlight recent progress of our work in the synthesis, processing and electrochemical characterization of molecularly-capped ternary nanoalloy catalysts, focusing on the enhanced electrocatalytic activity of Pt-based ternary nanoalloy catalysts for Oxygen Reduction Reaction in fuel cells. Selected examples of ternary nanoparticle catalysts for electrocatalytic Oxygen Reduction Reaction will be discussed. While important insights have been gained from studies of detailed structural aspects based a variety of techniques, this report summarizes some of the major findings in the studies of the electrochemical and electrocatalytic properties of the ternary nanoalloys to highlight the importance of ternary composition for the design and preparation of electrocatalysts.
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Ternary Alloy Electrocatalysts for Oxygen Reduction Reaction
Journal of Electrochemistry, 2012Co-Authors: Jin Luo, Lefu Yang, Binghui Chen, Chuan-jian ZhongAbstract:Proton exchange membrane fuel cell represents an important electrochemical energy conversion device with many attractive features in terms of efficiency of energy conversion and minimization of environmental pollution. However, the large overpotential for Oxygen Reduction Reaction at the cathode and the low activity, poor durability and high cost of platinum-based catalysts in the fuel cells constitute a focal point of major barriers to the commercialization of fuel cells. The development of nanostructured catalysts shows promises to addresses some of the challenging problems. The ability to engineer the composition and nanostructure of nanoalloy catalysts is important for developing active, robust and low-cost catalysts for fuel cell applications. This article highlights some of the recent insights into the catalytic properties of ternary nanoalloy catalysts prepared by molecularly-engineered synthesis and thermochemically-controlled processing, focusing on Oxygen Reduction Reaction in fuel cells. This approach has demonstrated the abilities to control size, composition, and nanoscale alloying of binary and ternary nanoalloys. A highly-active ternary nanoalloy catalyst consisting of platinum, nickel and cobalt that is supported on carbon (PtNiCo/C) will be discussed as an example, highlighting the importance of nanoscale tuning of structures and composition for the design of fuel cell catalysts. The mass activity of selected PtNiCo/C catalysts has been shown much higher electrocatalytic activity than those observed for their binary counterparts and commercial Pt/C catalysts. Selected examples will also be shown that the catalytic activity can be tuned by the ternary composition. The structural and synergistic properties of the ternary nanoalloy catalysts for the enhancement of the electrocatalytic activity will also be discussed.
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Structural and electrocatalytic properties of PtIrCo/C catalysts for Oxygen Reduction Reaction
ACS Catalysis, 2011Co-Authors: Rameshwori Loukrakpam, Minhua Shao, Jin Luo, Jun Yin, Bridgid N. Wanjala, Bin Fang, Lesia V. Protsailo, Tetsuo Kawamura, Yongsheng Chen, Valeri PetkovAbstract:This paper describes the results of an investigation of the synthesis of PtIrCo nanoparticles (2−3 nm) for electrocatalytic Oxygen Reduction Reaction. The carbon-supported PtIrCo catalysts (PtIrCo/C) were thermally treated at temperatures ranging from 400 to 900 °C. The size, composition, and atomic-scale structures of the PtIrCo/C catalysts were characterized for establishing their correlation with the electrocatalytic activity toward Oxygen Reduction Reaction. The specific activity was found to increase by a factor of 3−5 for the PtIrCo/C catalysts in comparison with Pt/C catalysts. A correlation was identified between the specific activity and the nanoparticle’s fcc-type lattice parameter. The specific activity increases whereas the fcc-type lattice parameter decreases with the thermal treatment temperature. This correlation was further substantiated by analyzing the interatomic spatial parameters in the trimetallic nanoparticles based on X-ray absorption fine structure spectroscopic and high-energy XR...
