What is a catalyst?
A catalyst accelerates or speeds up a chemical reaction without being consumed. AuTEK is active in the field of heterogeneous catalysis namely using solid materials to catalyse gas or liquid phase reactions. In the US alone sales of process catalysts are over $1 billion, the major uses being in petroleum refining, chemical production, and automotive / exhaust gas treatment.
Background to gold catalysts
Traditionally, gold metal was thought to be too inert and noble to provide active surfaces for catalysing chemical reactions. However, it has been shown that if gold metal is highly dispersed as clusters of 2 – 10 nanometers in size (1nm = 10-9m), containing 250 – 31 000 gold atoms, and the dispersed gold is supported on metal oxides (e.g. TiO2), very potent catalysts are formed for several reactions. Most notably, gold catalyses the oxidation of carbon monoxide to carbon dioxide at ambient and even sub-ambient temperatures. This makes gold the most active known catalyst to remove this highly toxic pollutant from air at room temperature.
This implies that gold catalysts can be used in gas masks and air-conditioners and other devices where pollution removal is vital. Apart from its health and environmental concerns, carbon monoxide has also been identified as one of the major stumbling blocks in the creation of the hydrogen economy and the subsequent widespread use of fuel cells (e.g. vehicles). Small amounts of carbon monoxide present in the hydrogen fuel are responsible for the poisoning and subsequent poor performance of a fuel cell. Gold catalysts offer the ability to oxidise the performance retarding carbon monoxide converting it to ‘inert’ carbon dioxide thereby protecting fuel cell efficiency.
To find out what other reactions gold may also catalyse please explore the following links:
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