United Technologies Corporation

Vinod M Jalan

Calvin L Bushnell

Douglas A Landsman

John M Lee

A novel catalyst comprises an alloy of a noble metal and vanadium. The catalyst is particularly useful in an electrochemical cell cathode electrode. The method for making the alloy involves reacting a vanadium compound with sodium dithionite to form a sol of a finely dispersed vanadium sulfite complex, and then reacting noble metal particles with the complex in a reducing environment.

Noble metal/vanadium alloy catalyst and method for making

A novel and improved fuel cell electrode includes a finely divided noble metal-base metal alloy catalyst. The catalytic activity of noble metal in the electrode is greater than the catalytic activity of the same unalloyed noble metal. Theoretically any base metal may be advantageously alloyed with the noble metal and will yield improved catalytic activity. Preferably the finely divided alloy is supported.

Electrochemical cell electrodes incorporating noble metal-base metal

Finely divided noble metal-refractory metal alloys and methods for making them are disclosed. As catalysts these alloys have greater activity than a catalyst of the same unalloyed noble metal and may be advantageously used as electrodes for fuel cells particularly when supported. The method for making supported catalysts involves a simple and inexpensive procedure for converting a supported, finely divided noble metal catalyst to the desired alloy. In a preferred embodiment the process includes intimately contacting the supported noble metal catalyst with a finely divided refractory metal oxide, the metallic component of which is capable of enhancing the activity of the catalyst when alloyed therewith, and then heating to a sufficiently high temperature, preferably in a reducing atmosphere, to reduce the oxide and simultaneously form a finely divided, supported alloy of the noble metal and the metallic component of the oxide.

Noble metal-refractory metal alloys as catalysts and method for making

The rate of platinum recrystallization of a platinum supported on carbon catalyst is reduced by depositing porous carbon on and around the supported platinum crystallites. The reduced rate of platinum recrystallization results in higher platinum surface areas over a period of time and therefore improves the performance of the catalyst. The porous carbon can be deposited by any suitable technique, a preferred method being to heat the supported platinum in the presence of carbon monoxide to decompose the carbon monoxide thereby depositing carbon on and around the platinum crystallites.

Catalyst and method for making

The rate of platinum recrystallization of a platinum supported on carbon catalyst is reduced and the activity of the catalyst is increased by depositing porous carbon on and around the supported platinum crystallites and then heating the catalyst in an inert atmosphere or vacuum at a high temperature.

Platinum catalyst and method for making

Method for the production of highly dispersed electrochemically active platinum particles having an average diameter below about 50 A for use in electrodes for fuel cells. Platinum particles are formed by mixing chloroplatinic acid and sodium dithionite in water to provide a platinum containing colloidal dispersion which may be absorbed on a support material. Hydrogen peroxide can be mixed with the chloroplatinic acid and sodium dithionite to improve the stability of the platinum containing colloidal dispersion.

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Manchester, CT, United States of America

Vinod M Jalan