Here’s a explanation of catalytic poisons:
What They Are
- Catalytic poisons are substances that stop or slow down a catalyst.
- They block the active sites of the catalyst so reactants cannot react.
Examples
- Platinum (Pt) catalyst + sulfur (H₂S) → hydrogenation stops.
- Iron (Fe) catalyst + arsenic or sulfur → ammonia production decreases.
- Nickel (Ni) catalyst + carbon monoxide (CO) → hydrogenation slows down.
Key Points
- Poison does not react itself.
- Can temporarily or permanently deactivate the catalyst.
- Important to avoid poisons in industrial processes.
In short: Catalytic poisons “kill” catalysts by blocking their active sites, so reactions slow down or stop.