CATALYST SYSTEM FOR FLOW REACTOR AND METHOD FOR CATALYTIC OXIDATION OF AMMONIA Russian patent published in 2024 - IPC B01J23/40 B01J23/42 B01J23/44 B01J23/46 B01J23/652 B01J23/755 B01J23/52 C01B21/26 

FIELD: chemistry; physics.

SUBSTANCE: present invention relates to a catalyst system for flow reactors, which is characterized by a sequence of noble metal alloys used in catalyst gauzes which form a catalyst system. Invention also relates to a method for catalytic combustion of ammonia. Described is an ammonia oxidation catalyst system for a flow reactor, comprising at least three groups of catalyst gauzes arranged one after another in the flow direction, wherein each group of catalyst gauzes is formed from at least one catalyst gauze, consisting in each case of at least one wire of noble metals, and the first group of catalyst gauzes comprises at least one catalyst gauze consisting of at least one first wire of noble metals made from a platinum alloy, wherein the platinum alloy, in addition to impurities, consists of 80–98 wt.% of platinum, 2–20 wt.% of rhodium and 0–20 wt.% of palladium; second group of catalyst gauzes comprises at least one catalyst gauze consisting of at least one second wire of noble metals made from a palladium alloy, wherein the palladium alloy of the second wire from noble metals, in addition to impurities, consists of 70–97 wt.% of palladium, 0–10 wt.% of rhodium and 3–30 wt.% of at least one additional metal, wherein at least one additional metal is selected from a group consisting of nickel, tungsten, platinum and gold; and a third group of catalyst gauzes comprises at least one catalyst gauze consisting of at least one third noble metal wire made from a palladium alloy, wherein the palladium alloy of the third noble metal wire, in addition to impurities, consists of 72–97 wt.% of palladium, 0–10 wt.% of rhodium and 3–28 wt.% of at least one additional metal, wherein at least one additional metal is selected from a group consisting of nickel, tungsten, platinum and gold, wherein content of rhodium in wires from noble metals of catalyst gauze groups decreases or remains unchanged in direction of flow, and content of palladium in wires from noble metals of groups of catalyst gauzes increases in direction of flow. Also described is a method for catalytic oxidation of ammonia, in which fresh gas containing at least ammonia is passed through said catalyst system.

EFFECT: catalyst system for a flow reactor, in which content of noble metal as a whole can be relatively small, and used noble metal can be used with maximum efficiency.

15 cl, 1 dwg, 3 tbl