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US 9,755,244 B2Granted
Conductive thin film for carbon corrosion protection
AssigneeGM Global Technology Operations LLC
InventorsBalasubramanian Lakshmanan, Jingxin Zhang
Life of this patent
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Abstract
A method for making corrosion resistant carbon nanoparticles includes a step of heating a carbon powder to a predetermined temperature. The carbon powder includes carbon particles having an average spatial dimension from about 10 to 100 nanometers. The carbon powder is contacted with a vapor of a metal-containing compound. The carbon powder is then contacted with a vapor of an activating compound. These steps are repeated plurality of times to form a metal-containing layer on the carbon particles.
Claims19
A method comprising:
- a) heating a carbon powder to a predetermined temperature, the carbon powder including carbon particles having an average spatial dimension from about 10 to 100 nanometers;
- b) contacting the carbon powder with a vapor of a metal-containing compound selected from the group consisting of tin-containing compounds, titanium-containing compounds, tantalum-containing compounds, niobium-containing compounds, and tungsten-containing compounds;
- c) contacting the carbon powder with a vapor of an activating compound;
- d) repeating steps b) and c) a sufficient number of times to form a metal-containing layer on the carbon particles having a thickness that is greater than or equal to σ1 and less than or equal to σ2 wherein σ1 is a thickness at which the carbon corrosion current is reduced to less than 20 percent of its maximum value and σ2 is a thickness at which the electrical conductivity is within 20 percent of its maximum value with σ1 being less than σ2;
- e) depositing a precious metal on the metal-containing layer;
- and
- f) incorporating the carbon particles with the metal-containing layer and the precious metal thereon into an electrocatalyst layer for a fuel cell.
4 more elements
A method comprising:
- a) heating a carbon powder to a predetermined temperature, the carbon powder include carbon particles having an average spatial dimension from about 10 to 100 nanometers;
- b) contacting the carbon powder with a vapor of a titanium tetrahalide;
- c) contacting the carbon powder with a vapor of an activating compound having an OH group, wherein the activating compound is a C1-6 alcohol;
- d) repeating steps b) and c) a sufficient number of times to form a titanium oxide layer on the carbon particles having a thickness that is greater than or equal to σ1 and less than or equal to σ2 wherein σ1 is a thickness at which the carbon corrosion current is reduced to less than 20 percent of its maximum value and σ2 is a thickness at which the electrical conductivity is within 20 percent of its maximum value with σ1 being less than σ2;
- e) depositing platinum on the titanium oxide layer;
- and
- f) incorporating the carbon particles with the titanium oxide layer and platinum thereon into an electrocatalyst layer for a fuel cell.
4 more elements
A method comprising:
- a) heating a carbon powder to a predetermined temperature, the carbon powder include carbon particles having an average spatial dimension from about 10 to 100 nanometers;
- and
- b) contacting the carbon powder with a vapor of a metal-containing compound and a vapor of an activating compound to form a metal-containing layer on the carbon particles by chemical vapor deposition, the metal-containing compound being selected from the group consisting of tin-containing compounds, titanium-containing compounds, tantalum-containing compounds, niobium-containing compounds, and tungsten-containing compounds wherein the activating compound is a C1-6 alcohol;
- c) depositing a precious metal on the metal-containing layer;
- and
- d) incorporating the carbon particles with the metal-containing layer and the precious metal thereon into an electrocatalyst layer for a fuel cell wherein step b) is repeated a sufficient number of times to form a metal containing layer on the carbon particles having a thickness that is greater than or equal to σ1 and less than or equal to σ2 wherein σ1 is a thickness at which the carbon corrosion current is reduced to less than 20 percent of its maximum value and σ2 is a thickness at which the electrical conductivity is within 20 percent of its maximum value with σ1 being less than σ2.
3 more elements
Dependencies are inferred from the claim text.