Patent application number | Description | Published |
20100197490 | Platinum-Coated Non-Noble Metal-Noble Metal Core-Shell Electrocatalysts - Core-shell particles encapsulated by a thin film of a catalytically active metal are described. The particles are preferably nanoparticles comprising a non-noble core with a noble metal shell which preferably do not include Pt. The non-noble metal-noble metal core-shell nanoparticles are encapsulated by a catalytically active metal which is preferably Pt. The core-shell nanoparticles are preferably formed by prolonged elevated-temperature annealing of nanoparticle alloys in an inert environment. This causes the noble metal component to surface segregate and form an atomically thin shell. The Pt overlayer is formed by a process involving the underpotential deposition of a monolayer of a non-noble metal followed by immersion in a solution comprising a Pt salt. A thin Pt layer forms via the galvanic displacement of non-noble surface atoms by more noble Pt atoms in the salt. The overall process is a robust and cost-efficient method for forming Pt-coated non-noble metal-noble metal core-shell nanoparticles. | 08-05-2010 |
20100216632 | High Stability, Self-Protecting Electrocatalyst Particles - High-stability, self-protecting particles encapsulated by a thin film of a catalytically active noble metal are described. The particles are preferably nanoparticles comprising a passivating element having at least one metal selected from the group consisting of columns IVB, VB, VIB, and VIIB of the periodic table. The nanoparticle is preferably encapsulated by a Pt shell and may be either a nanoparticle alloy or a core-shell nanoparticle. The nanoparticle alloys preferably have a core comprised of a passivating component alloyed with at least one other transition metal. The core-shell nanoparticles comprise a core of a non-noble metal surrounded by a shell of a noble metal. The material constituting the core, shell, or both the core and shell may be alloyed with one or more passivating elements. The self-protecting particles are ideal for use in corrosive environments where they exhibit improved stability compared to conventional electrocatalyst particles. | 08-26-2010 |
20110151356 | Electrocatalyst for Oxygen Reduction with Reduced Platinum Oxidation and Dissolution Rates - The invention relates to platinum-metal oxide composite particles and their use as electrocatalysts in oxygen-reducing cathodes and fuel cells. The invention particularly relates to methods for preventing the oxidation of the platinum electrocatalyst in the cathodes of fuel cells by use of these platinum-metal oxide composite particles. The invention additionally relates to methods for producing electrical energy by supplying such a fuel cell with an oxidant, such as oxygen, and a fuel source, such as hydrogen. | 06-23-2011 |
20130034803 | Electrochemical Synthesis of Elongated Noble Metal Nanoparticles, such as Nanowires and Nanorods, on High-Surface Area Carbon Supports - Elongated noble-metal nanoparticles and methods for their manufacture are disclosed. The method involves the formation of a plurality of elongated noble-metal nanoparticles by electrochemical deposition of the noble metal on a high surface area carbon support, such as carbon nanoparticles. Prior to electrochemical deposition, the carbon support may be functionalized by oxidation, thus making the manufacturing process simple and cost-effective. The generated elongated nanoparticles are covalently bound to the carbon support and can be used directly in electrocatalysis. The process provides elongated noble-metal nanoparticles with high catalytic activities and improved durability in combination with high catalyst utilization since the nanoparticles are deposited and covalently bound to the carbon support in their final position and will not change in forming an electrode assembly. | 02-07-2013 |
20130056359 | APPARATUS AND METHOD FOR THE SYNTHESIS AND TREATMENT OF METAL MONOLAYER ELECTROCATALYST PARTICLES IN BATCH OR CONTINUOUS FASHION - An apparatus and method for the synthesis and treatment of electrocatalyst particles in batch or continuous fashion is provided. In one embodiment, the apparatus is comprised of a three-electrode cell which includes a reference electrode, a counter electrode, and a working electrode. The working electrode is preferably a cylindrical vessel having an electrically conductive region. The electrode assembly is introduced into a slurry containing metal ions and a plurality of particles. During operation an electrical potential is applied and the working electrode is rotated at a predetermined speed. When particles in the slurry collide with the electrically conductive region the transferred charge facilitates deposition of an ad-layer of the desired metal. In this manner film growth can commence on a large number of particles simultaneously. This process is especially suitable as a commercial thin film deposition process for forming catalytically active layers on nanoparticles for use in energy conversion devices. | 03-07-2013 |
20150017565 | Core-Shell Fuel Cell Electrodes - Embodiments of the disclosure relate to electrocatalysts. The electrocatalyst may include at least one gas-diffusion layer having a first side and a second side, and particle cores adhered to at least one of the first and second sides of the at least one gas-diffusion layer. The particle cores includes surfaces adhered to the at least one of the first and second sides of the at least one gas-diffusion layer and surfaces not in contact with the at least one gas-diffusion layer. Furthermore, a thin layer of catalytically atoms may be adhered to the surfaces of the particle cores not in contact with the at least one gas-diffusion layer. | 01-15-2015 |
20150255799 | Apparatus and Method for the Synthesis and Treatment of Metal Monolayer Electrocatalyst Particles in Batch or Continuous Fashion - An apparatus and method for the synthesis and treatment of electrocatalyst particles in batch or continuous fashion is provided. In one embodiment, the apparatus is comprised of a three-electrode cell which includes a reference electrode, a counter electrode, and a working electrode. The working electrode is preferably a cylindrical vessel having an electrically conductive region. The electrode assembly is introduced into a slurry containing metal ions and a plurality of particles. During operation an electrical potential is applied and the working electrode is rotated at a predetermined speed. When particles in the slurry collide with the electrically conductive region the transferred charge facilitates deposition of an adlayer of the desired metal. In this manner film growth can commence on a large number of particles simultaneously. This process is especially suitable as a commercial thin film deposition process for forming catalytically active layers on nanoparticles for use in energy conversion devices. | 09-10-2015 |
20150303488 | Electrochemical Synthesis of Elongated Noble Metal Nanoparticles, such as Nanowires and Nanorods, on High-Surface Area Carbon Supports - Elongated noble-metal nanoparticles and methods for their manufacture are disclosed. The method involves the formation of a plurality of elongated noble-metal nanoparticles by electrochemical deposition of the noble metal on a high surface area carbon support, such as carbon nanoparticles. Prior to electrochemical deposition, the carbon support may be functionalized by oxidation, thus making the manufacturing process simple and cost-effective. The generated elongated nanoparticles are covalently bound to the carbon support and can be used directly in electrocatalysis. The process provides elongated noble-metal nanoparticles with high catalytic activities and improved durability in combination with high catalyst utilization since the nanoparticles are deposited and covalently bound to the carbon support in their final position and will not change in forming an electrode assembly. | 10-22-2015 |