StellarCatalysts speed up reactions without being permanently consumed. In general, catalysts work by lowering the activation energy or by increasing the number of effective collisions through better orientation of reactants. Because they make it easier for the reaction to occur, they increase the reaction rate. However, the amount of catalyst stays relatively constant overall because it is typically used in one step and regenerated in another.
Different kinds of catalysts work in different ways. Some catalysts bind to reactants and help orient them properly, which can create easier pathways and different intermediates. Enzymes are a major biological example. Other catalysts may donate or accept protons, as in acid-base catalysis. Surface catalysts work by holding reactants on a solid surface, often a metal, so they move in a more limited space and are more likely to collide effectively. Platinum in catalytic converters is a common example.
Example 1: If a catalyst lowers the activation energy, more particles can successfully react at the same temperature, so the rate increases.
Example 2: An enzyme can bind reactants in a specific orientation, making the reaction happen more easily and more quickly.