catalyst

/ˈkætəlɪst/ (bre, ipa) · /ˈkætəlɪst/ (ame, ipa) · /ˈka-tə-ləst/ (ame, mw)

catalyst — noun

1. in chemistry, any material that quickens the speed of a reactive process while r

1.名詞B2
釋義

in chemistry, any material that quickens the speed of a reactive process while remaining chemically unchanged itself — for instance, the enzymes in your mouth break down food far more quickly than would happen on their own.

例句

Platinum is often used as a catalyst in car exhaust systems to remove harmful gases.

catalyst in [system] for speeding reactions

Without the right catalyst, the two liquids would sit in the flask without reacting at all.

同義詞
  • enzyme

    a specific biological catalyst found in living organisms; narrower than catalyst

  • accelerant

    a substance that speeds a chemical process; less common in formal chemistry writing

  • agent

    a broader term for something that produces an effect; less specific to speeding reactions

反義詞
  • inhibitor

    a substance that slows down or stops a chemical reaction

文法句型

catalyst for [process]

catalyst in [reaction]

用法筆記

In chemistry, the noun is often paired with a specific metal or compound name ("an iron catalyst", "a palladium catalyst"). Common collocations include "act as a catalyst", "serve as a catalyst", and "catalyst for [a specific reaction]".

常見錯誤

❌The heat was a catalyst for boiling the water.
✅The heat was the energy source for boiling the water.
💡Boiling is a physical change, not a chemical reaction, so 'catalyst' does not apply here.

2. an event, a person, or an action that drives a major shift or transformation to

2.名詞B2
釋義

an event, a person, or an action that drives a major shift or transformation to unfold more rapidly or with greater intensity than would otherwise occur — for example, a protest that leads to new laws, or a leader whose arrival sparks reform within a company.

例句

The earthquake became a catalyst for rebuilding the city's old and unsafe infrastructure.

catalyst for [positive/negative outcome] — event as trigger

Aiko's passionate speech was the catalyst that pushed the student council to demand better cafeteria food.

同義詞
  • trigger

    an event that sets something in motion; suggests a more immediate cause than catalyst

  • spark

    a small event that starts a much larger development; more dramatic than catalyst

  • impetus

    a force that encourages something to happen; more abstract and formal

  • stimulus

    something that encourages activity or growth; broader in application

反義詞
  • obstacle

    something that blocks or slows change rather than accelerating it

  • deterrent

    a factor that discourages action or change from happening

文法句型

catalyst for [change]

catalyst of [transformation]

用法筆記

In figurative use, the noun is commonly followed by 'for' or 'of' ("a catalyst for change", "a catalyst of reform"). The person or event is not necessarily the direct cause; rather, it triggers or accelerates a process that was already under way.

常見錯誤

❌Ravi was the catalyst who cooked dinner.
✅Ravi was the catalyst who got the team to finally address the budget problem.
💡'Catalyst' implies triggering significant change or action, not just doing an ordinary task.