A catalyst is a substance or material that accelerates the rate of a chemical reaction without itself being consumed by the reaction. One of the most exciting things about catalysis by gold are the low 'light off' temperatures that are achieved (that is the temperature at which the catalyst becomes functional).  This enables gold to be used in the following low temperature applications:

Respirators for protection from CO poisoning

Respirators are required in emergency situations for protecting firefighters and miners from carbon monoxide poisoning near fires and boilers, etc in both domestic and working situations. Novax Materials manufacturers one such device using gold catalyst technology (see below).

Pollution control in living spaces

Gold catalysts are highly active for the oxidation of many components in ambient air at low temperatures, particularly carbon monoxide and nitrogen-containing malodorous compounds such as trimethylamine. This ability offers scope for applications related to air quality improvement and control of odours, be they in buildings, transport or other related applications. Air-cleaning devices are needed for removing carbon monoxide and trace amounts of VOCs and ozone from ambient air indoor office space (due to smoking, etc) and in confined spaces such as submarines or space crafts on long missions. This is a very important issue and the scope here for commercial applications is very large; significant patents have been published.

Gold on iron oxide catalyst used in Japan (courtesy of AIST, Japan)

Gold catalysts have already been used commercially in Japan for the removal of the odours from toilets. The gold on iron oxide catalyst being used to oxidise nitrogen containing odour compounds.