Formation of iridium carbonyl complex in NaY zeolite

Abstract The structure of iridium carbonyl complexes trapped within the zeolite cavities and the reactivity of these species towards the methanol carbonylation have been investigated. Ir(NH3)5Cl2+-exchanged NaY zeolite upon thermal decomposition is converted into an Ir(OH)x species. The carbonylation of iridium was followed by quantitative measurement of the 12CO uptake, infrared spectra of the reaction with 12CO, 13CO, and a mixture of 12CO13CO. Ir(I)(CO)3 was found to be very active and selective for the vapor phase carbonylation of methanol at atmospheric pressure in the presence of methyl iodide.