Carrier-supported catalyst and process for making monocarboxylic anhydrides

A carrier-supported catalyst for making monocarboxylic anhydrides by subjecting a suitable ester or ether to a carbonylation reaction, in which the carrier has a noble metal/chelate-compound formed of a noble metal compound selected from the 8th subgroup of the Periodic System of the elements and a chelator containing organonitrogen, organophosphorus, organoarsenic or organosulfur groups applied to it, the chelator being a compound of the formula:

• (a) Y--(CH.sub.2).sub.n --Y
• (b) Y--CH.dbd.CH--Y
• (c) O.sub.2 P--CH.dbd.CH--PO.sub.2
• (d) O.sub.2 As--CH.dbd.CH--AsO.sub.2
• (e) O.sub.2 P--CH.sub.2 --CH.sub.2 --PO--CH.sub.2 --CH.sub.2 --PO--CH.sub.2 --CH.sub.2 --PO.sub.2
• (f) O.sub.2 P--CH.sub.2 --CH.sub.2 --PO--CH.sub.2 --CH.sub.2 --PO.sub.2 ##STR6##
• (h) P(--CH.sub.2 CH.sub.2 --PO.sub.2).sub.3
• (i) R.sup.1 --C[--(CH.sub.2).sub.n --Y].sub.3 ##STR7## in which O stands for C.sub.6 H.sub.5 --;
• Y stands for --NR.sub.2.sup.2, an aryl group containing nitrogen, --PR.sub.2.sup.2, --AsR.sub.2.sup.2, --SR.sup.2 or --SH;
• R.sup.1 stands for --H, C.sub.1 -C.sub.5 -alkyl or --C.sub.6 H.sub.5 ;
• R.sup.2 stands for a C.sub.1 -C.sub.6 -alkyl, a C.sub.5 -C.sub.8 -cycloalkyl or --C.sub.6 H.sub.5 or C.sub.6 H.sub.5 CH.sub.2 --;
• n stands for 1 through 6;
• m stands for 0 through 8, and
• x stands for 1 or 2.