How do oil additives cause catalyst fouling?

Catalyst fouling or catalyst poisoning is a known issue with oil additives. But which additives? ZDDP (zinc) antiwear additives are known to cause this problem and this has lead to their decreasing use with recent updates to ACEA and API specifications. But what is the mechanism for this fouling?
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Rafe Britton is a lubrication consultant that turns machinery into well-oiled, reliable machinery. He helps clients achieve maximum uptime by setting up procurement processes such that they are oriented to lubrication reliablity, transforming their contamination control programs, selecting the correct lubricants for the application, training their workforce to a world-class level, and helping to turn oil analysis data into valuable insights. He firmly believes that there is an industry-wide knowledge gap regarding lubrication technologies and is aspiring to close this gap affordably by using digital tools.

[@LubricationExplained]

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[@AikiNinja1]

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[@Unknown-jl7mg]

great video as always

[@LubricationExplained]

Thanks!

[@vinhgolf]

in searching for zinc additives, i found your video and it is very informative. And which additives that you would recommend to for oil or zinc additives so that it will not effect the catalyst ? thanks in adance

[@DumitruUrsu]

by the way, there is a proven method of recovery of cats from poisoning, DOI - 10.1021/es040062f ; a 80 degrees Celsius wash with citric acid - I did it myself, and I passed the emissions tests (my car has ~250.000 km) ; there's also another wash, citric acid + oxalic acid (both relatively safe acids, pretty mild), but I can't find the article right now.

[@davidsteckley8846]

So using A3/B4. Probably should use a cat cleaner 4 times a year like cataclean says to use?

[@MunsKi]

can zddp increase TBN?

[@BenKlassen1]

Is it true that "high-mileage" formulations accelerate catalyst fouling because they have additional additives and aren't held to the same standards as standard formulations?

[@DumitruUrsu]

I've also heard of that silicone greases are very poisonous to catalytic converters, is that true?

[@weatherwatcher5303]

I have a sulphur smell from exhaust

[@mookieblaylock2589]

You should mention important thing that this happens only when engine consume oil. New oil specs and newest eco demands killing the modern engines within 5-7 years with 120-150K miles.

[@LubricationExplained]

Good point, although all engines consume oil to some extent. It's just the rate of consumption that differs.

[@bruceparr1678]

Just use R30.