Nitrogen, catalytic cycles that destroy

The involvement of reactive nitrogen, reactive hydrogen, and reactive chlorine in catalytic cycles that destroy ozone has been known for about 20 years. These cycles have the form... 

FCC catalysts are deactivated via several mechanisms," which all result in a loss in activity and a change in yield selectivity Catalyst will age, meaning change chemical and physical structure due to the (hydro) thermal conditions during the 10,000 to 50,000 reaction and regeneration cycles it will endure. The catalysts can also be poisoned, whereby the active sites are covered by coke and/or polars (nitrogen) that neutralize the catalytic activity or by metals (vanadium, nickel, sodium) which can destroy or alter the activity. 

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