Platinum- and platinum alloy-coated palladium and palladium alloy particles and uses thereof
AssigneeBrookhaven Science Associates, LLC
InventorsRadoslav Adzic, Junliang Zhang, Yibo Mo, Miomir Vukmirovic
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Abstract
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.
Claims38
A particle composite comprising a palladium or palladium-alloy particle coated with a layer selected from the group consisting of an atomic submonolayer, monolayer, bilayer, or trilayer of zerovalent platinum atoms, or a combination thereof, wherein said palladium-alloy does not include platinum.
A suspension or dispersion comprising a particle composite suspended or dispersed in a liquid phase, wherein said particle composite comprises a palladium or palladium-alloy particle coated with a layer selected from the group consisting of an atomic submonolayer, monolayer, bilayer, or trilayer of zerovalent platinum atoms, or a combination thereof, wherein said palladium-alloy does not include platinum.
A catalyst comprising a particle composite comprising a palladium or palladium-alloy particle coated with a layer selected from the group consisting of an atomic submonolayer, monolayer, bilayer, or trilayer of zerovalent platinum atoms, or a combination thereof, wherein said palladium-alloy does not include platinum, wherein said particle composite is bound to a support.
A fuel cell comprising:
- (i) an oxygen-reducing cathode comprised of a nanoparticle composite comprising a palladium or palladium-alloy nanoparticle coated with a layer selected from the group consisting of an atomic submonolayer, monolayer, bilayer, or trilayer of zerovalent platinum atoms, or a combination thereof, wherein said palladium-alloy does not include platinum, and wherein said nanoparticle composite is bound to an electrically conductive support;
- (ii) an anode;
- (iii) an electrical contact connecting said oxygen-reducing cathode with said anode;
- and
- (iv) a proton-conducting medium mutually contacting said oxygen-reducing cathode and said anode.
A method for producing electrical energy, the method comprising:
- (i) contacting an oxygen-reducing cathode of a fuel cell with oxygen, wherein the oxygen-reducing cathode is comprised of a nanoparticle composite comprising a palladium or palladium-alloy nanoparticle coated with a layer selected from the group consisting of an atomic submonolayer, monolayer, bilayer, or trilayer of zerovalent platinum atoms, or a combination thereof, wherein said palladium-alloy does not include platinum, and wherein said nanoparticle composite is bound to an electrically conductive support;
- (ii) contacting an anode of said fuel cell with a fuel source;
- wherein said oxygen-reducing cathode is in electrical contact with said anode;
- and wherein said oxygen-reducing cathode and said anode are in chemical contact through mutual contact with a proton-conducting medium.
A method for reducing oxygen gas, the method comprising contacting a nanoparticle composite comprising a palladium or palladium-alloy nanoparticle coated with a layer selected from the group consisting of an atomic submonolayer, monolayer, bilayer, or trilayer of zerovalent platinum atoms, or a combination thereof, wherein said palladium-alloy does not include platinum, with oxygen gas.
Dependencies are inferred from the claim text.