US Patent 8986638 Catalytic oxidation of sulphide species

The present invention relates to a process for the catalytic oxidation of sulphide, mono- and/or dihydrogen sulphide, comprising the step ofcontacting the sulphide, mono- and/or dihydrogen sulphide in the presence of oxygen with a chelate complex comprising(i) a metal cation selected from the group consisting of Fez+, Mnz+, Niz+ and Coz+, where z=2 or 3, and(ii) a chelate ligand containing a porphyrin, a phthalocyanine or a porphyrazine ring coordinated to the metal cation, and at least one cationic substituent covalently attached to the ring in the chelate ligand.