Brookhaven Science Associates, Lcc

Gm Global Technolgoy Operations, Inc.

Junliang Zhang

Radoslav R Adzic

Miomir Vukmirovic

Frederick T Wagner

Yibo Mo

Zhongyi Liu

Zhiqiang Yu

Timothy J Fuller

Michael R Schoeneweiss

Michael Kevin Carpenter

Susan Yan

Matthew Dioguardi

Ruichun Jiang

Kotaro Sasaki

A method for forming an electrocatalyst for fuel cell applications comprises electrolessly depositing a first plurality of nickel particles onto carbon-support particles. The nickel particles are formed from a nickel ion-containing aqueous solution. At least a portion of the nickel particles are replaced with platinum via a galvanic displacement reaction to form a second plurality of nickel particles coated with a platinum layer. During this displacement reaction step, the nickel particles are heated to a temperature sufficient to form the platinum layer. Finally, the second plurality of nickel particles is optionally incorporated into a cathode layer of a fuel cell.

Graphite particle-supported Pt-shell/Ni-core nanoparticle electrocatalyst for oxygen reduction reaction

A fuel cell membrane and a method of making the same. The membrane includes at least one non-reinforced layer and at least one reinforced layer. Both layers include a proton-conductive ionomer, while the reinforced layer additionally includes nanofiber-supported catalyst that improve mechanical and chemical durability of the membrane. The nanofiber-supported catalyst is made up of structural fibers onto which an electrocatalyst is coated, deposited or otherwise formed. The structural nanofibers give increased strength and stiffness to the layers that include them, while the electrocatalyst helps to resist electrochemical degradation to the membranes that include them. Such a membrane may form the basis of a fuel cell's membrane electrode assembly.

Nanofiber supported catalysts as membrane additives for improved fuel cell durability

An apparatus and method for synthesis and treatment of electrocatalyst particles in batch or continuous fashion is provided. In one embodiment, the apparatus comprises a sonication bath and a two-compartment chamber submerged in the sonication bath. The upper and lower compartments are separated by a microporous material surface. The upper compartment comprises a cover and a working electrode (WE) connected to a Pt foil contact, with the foil contact connected to the microporous material. The upper chamber further comprises reference counter electrodes. The lower compartment comprises an electrochemical cell containing a solution of metal ions. In one embodiment, the method for synthesis of electrocatalysts comprises introducing a plurality of particles into the apparatus and applying sonication and an electrical potential to the microporous material connected to the WE. After the non-noble metal ions are deposited onto the particles, the non-noble metal ions are displaced by noble-metal ions by galvanic displacement.

Method and electrochemical cell for synthesis and treatment of metal monolayer electrocatalysts metal, carbon, and oxide nanoparticles ion batch, or in continuous fashion

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.

Platinum-coated non-noble metal-noble metal core-shell electrocatalysts

A method of coating carbon based electrodes and thick electrodes without mud-cracking is described. The electrode ink is deposited on a decal substrate, and transferred to a hot press before the electrode ink is completely dried. The partially dried electrode ink is hot pressed to the membrane to form a membrane electrode assembly. A membrane electrode assembly including a polymer membrane; and a pair of crack-free electrode layers on opposite sides of the polymer membrane, each of the pair of electrode layers having a thickness of at least about 50 &#x3bc;m is also described.

Method for membrane electrode assembly fabrication and membrane electrode assembly

A membrane/electrode assembly for fuel cell applications includes an ion conducting polymer and a porphyrin-containing compound at least partially dispersed within the ion conducting polymer, a first electrode and a second electrode. At least one of the first and second electrodes also includes the porphyrin-containing compound. The membrane/electrode assembly exhibits improved performance over membrane/electrode assembly not incorporating such porphyrin-containing compounds.

Cobalt(II) tetramethoxyphenylporphyrin (CoTMPP) ionomer stabilization to prevent electrode degradation

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.

Electrocatalyst for oxygen reduction with reduced platinum oxidation and dissolution rates

A method of treating electrically conductive nanoparticles using a dynamic processing electrochemical cell.

Method of treating nanoparticles using an intermittently processing electrochemical cell

An electrocatalyst is described. The electrocatalyst includes a core of a non-noble metal or non-noble metal alloy; and a continuous shell of a noble metal or noble metal alloy on the core, the continuous shell being at least two monolayers of the noble metal or noble metal alloy. Methods for making the electrocatalyst are also described.

Method for generating a shell of noble metal overlaid on a core of non-noble metal, and catalysts made thereby

The invention relates to platinum-coated particles useful as fuel cell electrocatalysts. The particles are composed of a noble metal or metal alloy core at least partially encapsulated by an atomically thin surface layer of platinum atoms. The invention particularly relates to such particles having a palladium, palladium alloy, gold alloy, or rhenium alloy core encapsulated by an atomic monolayer of platinum. In other embodiments, the invention relates to fuel cells containing these electrocatalysts and methods for generating electrical energy therefrom.

Electrocatalysts having platium monolayers on palladium, palladium alloy, and gold alloy core-shell nanoparticles, and uses thereof

The invention relates to gold-coated particles useful as fuel cell electrocatalysts. The particles are composed of an electrocatalytically active core at least partially encapsulated by an outer shell of gold or gold alloy. The invention more particularly relates to such particles having a noble metal-containing core, and more particularly, a platinum or platinum alloy core. In other embodiments, the invention relates to fuel cells containing these electrocatalysts and methods for generating electrical energy therefrom.

Electrocatalysts having gold monolayers on platinum nanoparticle cores, and uses thereof

The present invention relates to particle and nanoparticle composites useful as oxygen-reduction electrocatalysts. The particle composites are composed of a palladium or palladium-alloy particle or nanoparticle substrate coated with an atomic submonolayer, monolayer, bilayer, or trilayer of zerovalent platinum atoms. The invention also relates to a catalyst and a fuel cell containing the particle or nanoparticle composites of the invention. The invention additionally includes methods for oxygen reduction and production of electrical energy by using the particle and nanoparticle composites of the invention.

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Rochester, NY, United States of America

Junliang Zhang