Catalysis yog tus txheej txheem ntawm kev nce tus nqi ntawm cov tshuaj tiv thaiv tshuaj los ntawm kev ntxiv cov catalyst. Lub catalyst yog ib yam khoom uas tuaj yeem hloov cov tshuaj tiv thaiv ntawm lwm yam tshuaj yam tsis tau hloov nws cov huab hwm coj thiab tshuaj lom neeg ua ntej thiab tom qab cov tshuaj tiv thaiv, thiab tsis hloov cov tshuaj sib npaug. Catalysts ceev cov tshuaj tiv thaiv los ntawm kev muab lwm txoj kev tshuaj tiv thaiv nrog lub zog ua kom qis dua.
Lub catalyst feem ntau muaj peb ntu: ib qho khoom siv, kev txhawb nqa, thiab kev txhawb nqa. Lub active tivthaiv yog lub ntsiab ntawm lub catalyst, muab tshuaj lom neeg kev ua si; kev txhawb nqa ua raws li kev sib cais, khi, lossis kev txhawb nqa; thiab cov neeg txhawb nqa yog siv los txhim kho kev ua haujlwm ntawm cov catalyst.
Raws li lub xeev theem ntawm cov catalyst thiab reactants, catalysts tuaj yeem muab faib ua homogeneous catalysts thiab heterogeneous catalysts. Biocatalysts xws li enzymes feem ntau suav hais tias yog chav kawm cais. Tsis tas li ntawd, autocatalysis, qhov twg cov tshuaj tiv thaiv cov khoom lawv tus kheej catalyze cov tshuaj tiv thaiv, kuj muaj.
