How to poison the catalyst. What can be done?
In the reactants or catalyst mixed with a small amount of material, so that the catalyst catalytic capacity of a sharp decline or even loss, this phenomenon is called catalyst poisoning. For example, in the synthesis of ammonia feed gas containing CO, CO2 and H2S, PH3, water vapor and other impurities, can make iron catalyst poisoning; contact with the system of sulfuric acid, if arsenic and selenium oxide (As2O3, SeO2), can make vanadium catalyst Loss of activity. Therefore, it is necessary to purify the feed gas, prevent the poisoning of the catalyst, and also reduce the corrosion of the equipment. The phenomenon of catalyst poisoning is sometimes temporary, the removal of toxicants, the effectiveness of the catalyst can still be restored; sometimes it is permanent, without chemical treatment can not restore catalytic performance.
