Topic 4 of 5
Catalysts provide an easier reaction pathway
They change the rate without being used up overall.
O-Level 6092 (2026) / SEC G3 K324 (2027)
Pure onlyCatalysts provide an easier reaction pathway
They change the rate without being used up overall.
A catalyst increases reaction rate and is chemically unchanged overall at the end. It can take part in intermediate steps before being regenerated. It provides an alternative pathway with lower activation energy, so a larger fraction of collisions can succeed at the same temperature. It does not supply the reaction energy or increase the final yield from a fixed limiting reactant.
| Context | Catalyst or catalytic material |
|---|---|
| Haber ammonia synthesis | Iron |
| Hydrogenation of unsaturated oils | Nickel |
| Hydrogen peroxide decomposition | Manganese(IV) oxide |
| Sulfuric-acid manufacture | Vanadium(V) oxide, an example of a compound acting as an industrial catalyst |
| Catalytic converters | Metal catalysts speed conversion of exhaust pollutants |
| Biological reactions | Enzymes are biological catalysts |
On an energy profile, the catalysed route has a lower peak but the same reactant and product levels. Enzymes also increase rates, but their activity depends on conditions; heating them too much can change their structure and reduce activity. Do not treat every catalyst as able to work under any conditions.