The phenomenon where trace impurities in the reaction raw materials significantly reduce or lose the activity and selectivity of the catalyst. The essence of poisoning phenomenon is the chemical reaction between trace impurities and active centers of catalysts, forming inactive species. In gas-solid multiphase catalytic reactions, adsorption complexes are formed. One type is reversible poisoning or temporary poisoning, which can be restored by simple methods if the toxic substance has weak interaction with the active component. The other type is irreversible poisoning, which cannot be restored to activity by simple methods. In order to reduce the activity of side reactions, it is sometimes necessary to selectively poison the catalyst.
Catalysts may lose their activity during use due to various factors, one of which is poisoning. There are several possible causes of catalyst poisoning, including a small amount of impurities in the original family, strong adsorption (mostly chemical adsorption) on the active center, or chemical reactions with the active center, which can cause poisoning of the active center. In addition, such toxins may also be present in the reaction products; In the preparation process of catalysts, impurities contained in the carrier may interact with the active components and may also poison the active centers.
The phenomenon where trace impurities in the reaction raw materials significantly reduce or lose the activity and selectivity of the catalyst. The essence of poisoning phenomenon is the chemical reaction between trace impurities and active centers of catalysts, forming inactive species. In gas-solid multiphase catalytic reactions, adsorption complexes are formed. One type is reversible poisoning or temporary poisoning, which can be restored by simple methods if the toxic substance has weak interaction with the active component. The other type is irreversible poisoning, which cannot be restored to activity by simple methods. In order to reduce the activity of side reactions, it is sometimes necessary to selectively poison the catalyst.
Catalysts may lose their activity during use due to various factors, one of which is poisoning. There are several possible causes of catalyst poisoning, including a small amount of impurities in the original family, strong adsorption (mostly chemical adsorption) on the active center, or chemical reactions with the active center, which can cause poisoning of the active center. In addition, such toxins may also be present in the reaction products; In the preparation process of catalysts, impurities contained in the carrier may interact with the active components and may also poison the active centers.
