Cluster-derived FeIr/MgO catalysts prepared from [Et4N]2[Fe2Ir4(CO)16] and [Et4N]2[Fe2Ir2(CO)12] exhibit high activity in methanol synthesis from CO + H2. The catalyst performance improves significantly upon raising the Fe:Ir ratio in the precursor from 2:4 to 2:2; with the latter sample, at 488-523 K and 6.1 MPa, methanol productivities up to 100 mol/mol(Ir) h are obtained with selectivity around 90%. Preliminary extended X-ray absorption fine structure characterization suggests that the formation of active sites upon activation in hydrogen at 623 K, is related to the presence of highly dispersed iridium particles stabilized on the surface by interfacial iron.