An article in The Financial Times last week explored the possibilities of using gold as catalyst in automotive emissions scrubbings systems. The article came about after a technical conference held in South Africa focusing on gold s application in this vital industrial sector. While conceding that the low melting pint of gold made it unsuitable as a catalyst for scrubbing CO emissions from normal gasoline engines, it suggested that gold may work well for diesel engines emissions scrubbings. Johnson Matthey, one of the world s leading refiners of precious metals and manufacturer of autocatalysts, pointed out that gold is unlikely to ever usurp the platinum group metals in this type of application. While gold does have some catalytic properties, the catalytic activity of gold is rapidly lost at the elevated temperatures of automobile exhausts.
Platinum however is durable to occasional high temperature excursions.
Addressing the recent announcement by Honda that it would be using a new metal oxide technology to reduce platinum group usage in its Japan model Stepwagon, JM said that demand for pgms in the automotive industry is unlikely to fall. Advances in catalyst technology would play a more essential role in preventing pgm demand from escalating as rapidly as in recent years. Auto companies, with the help of their autocatalyst suppliers, continually aim for more cost effective emissions control systems. JM points out that rare earth metal oxides have been core components of catalyst technology for the last 15 years. They help to increase the catalytic activity of PGMs, so have been an important factor in controlling the amount of PGMs used in emissions systems.