Chemistry - C2 4.6 - Catalysts in action

Because even though catalysts are expensive, it is cheaper to have a catalyst than pay for the amount of energy needed without a catalyst. To get the same reaction without a catalyst would require higher temperatures and/or pressures.

Because many transition metals or their compounds are toxic, and the toxic could go into the drug which would be dangerous and could be poisonous. 

Catalysts can be cheaper for the chemical industry as without a catalyst the extra needed energy would be more expensive. To get the same amount of energy that would be created with a catalyst would be more expensive, you would have to have higher temperatures and/or pressures. 
Also, catalysts can help the environment as if there wasn't a catalyst the higher temperatures and/or pressures would often involve burning fossil fuels. So operating with a catalyst at lower temperatures and pressures conserves these non-renewable sources. Also, it stops more carbon dioxide entering the atmosphere. 

Most of the transition metals or their compounds used in catalysts are toxic. When they are used in a catalyst toxic gases can escape into the air, this will poison living things over time. For example, the platinum and palladium used in catalytic converters slowly escape from car exhausts. 

• Catalysts are used whenever possible in industry to increase rate of reaction and reduce energy costs.
• Traditional catalysts are often transition metals or their compounds, which can be toxic and harm the environment if they escape.
• Modern catalysts are being developed in industry which result in less waste and are safer for the environment.