Oxychlorination sources for regenerating dispersions of ligand-stabilized, palladium (II) halide complexes used as carbonylation catalysts

Claim 1

A process for regenerating spent carbonylation catalyst of ligand-stabilized palladium(II) halide complexes in quaternary ammonium, phosphonium and arsonium salts of trihalostannate(II) or trihalogermanate(II), the spent catalyst being obtained from the carbonylation of olefins, wherein said ligand stabilized catalysts are selected from the group consisting of: [(C 2 H 5 ) 4 N][SnCl 3 ]-PdCl 2 [P(C 6 H 5 ) 3]2 [(c 2 h 5 ) 4 n][snCl 3 ]-PdCl 2 [P(p-CH 3 .C 6 H 4 ) 3]2 [clCH 2 (C 6 H 5 ) 3 P][SnCl 3 ]-PdCl 2 [P(C 6 H 5 ) 3]2 [(n.C 4 H 9 ) N][SnCl 3 ]-PdCk 2 [P(C 6 H 5 ) 3]2 [(c 6 h 5 ) 4 as][SnCl 3 ]-PdCl 2 [P (C 6 H 5 ) 3]2 [(c 2 h 5 ) 4 n][geCl 3 ]-PdCl 2 [P(C 6 H 5 ) 3]2 [(c 2 h 5 ) 4 n][snCl 3 ]-PdCl 2 [P(p-CH 3 I.C 6 H 4 ) 3]2 , and [(C 7 H 15 ) 4 N][GeCl 3 ]-PdCl 2 [As(C 6 H 5 ) 3]2 , by the a. mixing said spent palladium carbonylation catalyst with inert solvent selected from the group consisting of chlorinated aliphatics, chlorinated aromatics, aromatics and carboxylic acid esters to form a reaction mixture, b. heating said reaction mixture at temperatures ranging from 20° to 200° C for a time of 0.1 to 48 hours, in a stream of hydrogen chloride plus a source of oxygen selected from the group consisting of oxygen and air, said volume ratio of hydrogen chloride ratio to oxygen or varying from 10:1 to 1:10, c. removing excess solvent under reduced pressure until a dried palladium catalyst is obtained, and d. adding additional stabilizing ligand to the dried catalyst wherein the stabilizing ligand is selected from the group consisting of tri henylphosphine, triphenylarsine, tri-p-tolylphosphine, and tri-p-methoxyphenylphosphine, said mole ratio of ligand added per gram atom of palladium varies from 1 to 10 moles of ligand per gram atom of palladium, until said spent ligand catalyst is regenerated.