Abstract: This invention concerns processes for the regeneration of carbonylation catalysts consisting of dispersions of ligand-stabilized palladium(II) halide complexes in quaternary ammonium, phosphonium and arsonium salts of trihalostannate(II) and trihalogermanate(II) using organic peroxides as the regenerating agent.STATEMENT OF THE INVENTIONThis invention pertains to the art of regenerating spent palladium carbonylation catalysts useful for the carbonylation of olefins.More particularly, this invention concerns the regeneration of certain carbonylation catalysts consisting of dispersions of ligand-stabilized palladium(II) halide complexes in quaternary ammonium, phosphonium and arsonium salts of trihalostannate(II) and trihalogermanate(II) using substantially anhydrous organic peroxide reagents.BACKGROUND OF THE INVENTIONThis invention concerns a process for regenerating certain palladium catalysts used in the carbonylation of olefins. Carbonylation refers here to the reaction of .alpha.