Methanol carbonylation in a liquid flow system catalyzed by a polymer-bound rhodium(I) complex

Abstract

The continuous liquid-phase carbonylation of methanol in the presence of methyliodide promotor is catalyzed by a copolymer-bound cis-dicarbonylrhodium(I) complex, which forms the fixed bed in a microcatalytic plug-flow reactor system. The copolymer support with a chelating ligand was prepared from 2-vinylpyridine, methyl acrylate and 5 mol-% cross-linking ethene diacrylate. The activity and stability of the catalyst was examined at 20 atm, and 140 and 120°C. In the reactor system used here (liquid flow system) the catalyst is not stable. From an initial rate of 1.1·10 −3 mol/s·g rhodium the rate decreases to approximately 3.7·10 −4 mol/s·g rhodium after six hours. At this activity level the catalyst seems stable, however, with an “intrinsic activity” (activity per gram rhodium), which is approximately 4.6 times lower than for the homogeneous catalyst.