Nanostellar, Inc. (Redwood City, CA) garnered U.S. Patents and
A method for producing a supported palladium-gold catalyst, according to Nanostellar includes the steps of preparing a mixture of support materials and a base solution, heating the mixture to a temperature above room temperature, adding a palladium salt solution and a gold salt solution to the mixture while maintaining the pH of the mixture to be greater than 7.0, and stirring the mixture for a period of time while maintaining the temperature of the mixture at a temperature above room temperature. The mixture is then filtered to separate out supported palladium-gold particles. This is followed by washing with warm de-ionized water and calcining the supported palladium-gold particles.
The palladium/gold catalyst provides an emission control catalyst for treating an engine exhaust comprising a supported catalyst containing metal particles consisting essentially of palladium and gold. While pollution from vehicle exhaust has decreased over the years from the use of catalytic converters and particulate filters, research into improved supported catalysts has been continuing as requirements for vehicle emission control have become more stringent and as vehicle manufacturers seek to use less amounts of precious metal in the supported catalysts to reduce the total cost of emission control.
Figure 2 from of catalytic converter with gold-palladium nanocatalysts from Nanostellar