Catalysts change the rate of chemical reactions without being changed themselves.
The catalytic process reduces the amount of energy needed for reactions to occur, thus making them more efficient. The economic importance of catalysis lies in the reaction chemistry that enables production of commodities such as petroleum products, plastics, pharmaceuticals, automobiles and chemicals. If the yields of catalytic processes were maximized, the energy needed to produce these 50 chemicals could be reduced by 0.47 quad. Producing the top 50 commodity chemicals releases an estimated 20.9 billion pounds of CO2 into the atmosphere either directly or via unwanted by-products that are later incinerated or converted. Increasing catalytic process efficiency is the key to reducing these emissions.